Optical disk, reproduction apparatus, and reproduction method

ABSTRACT

An optical disk includes: a data region; and a management region. The data region stores: at least one video object containing video information and audio information; and at least one audio object containing audio information. The management region stores first path information and second path information, the first path information indicating a first reproduction path including only the at least one video object, and the second path information indicating a second reproduction path including a combination of the at least one video object and the at least one audio object.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical disk for storing digitaldata of multimedia data including audio information and moving imageinformation that are associated with each other, as well as an apparatusand a method for reproducing the same.

2. Description of the Related Art

Conventionally, CDs (compact disks) and LDs (laser disks) are -known asoptical disks for storing and reproducing audio Information and/ormoving image information.

A CD is an optical disk having a diameter of 12 cm. A CD carries audioinformation stored thereon which has been quantized by using a linearPCM method. CDs are widely prevalent as a storage medium formusic-oriented applications.

An LD is an optical disk having a diameter of 30 cm. An LD carriesmoving image information stored thereon in the form of analog signals.LDs are widely prevalent as a storage medium for image-orientedapplications such as movies.

In addition to such uses, applications which cannot be distinguished tobe either simply music-oriented or image-oriented have emerged, e.g.,operas and the recently-evolved music clips (i.e., music accompanied byimages).

Herein, those uses which cannot be distinguished as eithermusic-oriented or image-oriented will be referred to as being directedto “image-accompanied music”.

In the case of applications of image-accompanied music, it is difficultto know which mode of viewing/listening a user may desire because oneuser may wish to only listen to the music without viewing the images,while another may wish to enjoy both the music and the images. It isalso possible for the same user to desire variable modes ofviewing/listening depending on each situation. For example, a user maywish to only listen to music in the case where the user runs animage-accompanied music application on a portable reproduction apparatuswhile moving around or on a reproduction apparatus mounted in anautomobile, but the same user may wish to enjoy both the music and theimages when running the image-accompanied music application on anon-portable reproduction apparatus at home.

However, in the case of playback of only the audio information of animage-accompanied music application, merely omitting the imageinformation reproduced from the Image-accompanied music application fromdisplay may result in an awkward reproduction of those voices or soundswhich would only be meaningful when reproduced along with images, e.g.,the voices and sounds of an interview in an music clip.

Furthermore, merely omitting from display the image informationreproduced from the image-accompanied music application may result in amalfunctioning of the reproduction apparatus due to the omission of theimages. For example, in the case where an image menu is omitted fromdisplay, it is. possible for the application to remain waiting for aninput responsive to the undisplayed image menu.

Furthermore, there may be a desire to enjoy higher-quality voices andsounds during audio reproduction than during video reproduction.

SUMMARY OF THE INVENTION

According to the present invention, there is provided an optical diskincluding: a data region; and a management region, wherein the dataregion stores: at least one video object containing video informationand audio information; and at least one audio object containing audioinformation, and wherein the management region stores first pathinformation and second path information, the first path informationindicating a first reproduction path including only the at least onevideo object, and the second path information indicating a secondreproduction path including a combination of the at least one videoobject and the at least one audio object.

In one embodiment of the invention, the second path information includesoffset information for designating a range to be reproduced of the audioinformation contained In the at least one video object.

In another embodiment of the invention, the quality of the audioinformation contained in the at least one audio object is higher thanthe quality of the audio information contained in the at least one videoobject.

According to the present invention, there is provided a reproductionapparatus for reproducing an optical disk in a reproduction mode, theoptical disk including a data region and a management region, the dataregion storing: at least one video object containing video informationand audio information; and at least one audio object containing audioinformation, wherein the management region stores first path informationand second path information, the first path information Indicating afirst reproduction path including only the at least one video object,and the second path information indicating a second reproduction pathincluding a combination of the at least one video object and the atleast one audio object, the reproduction apparatus including: areproduction mode determination section for determining whether thereproduction mode is a first reproduction mode for reproducing videoinformation and audio information or a second. reproduction mode forreproducing only audio information; and a reproduction section forreproducing the video information and the audio information contained inthe at least one video object along the first reproduction path in thecase where the reproduction mode is the first reproduction mode, andreproducing the audio information contained in the at least one videoobject and the audio information contained in the at least one audioobject along the second reproduction path in the case where thereproduction mode is the second reproduction mode.

In one embodiment of the invention, the second path information includesoffset information for designating a range to be reproduced of the audioinformation contained in the at least one video object, the reproductionapparatus reproducing a portion of the audio information contained inthe at least one video object in accordance with the offset information.

In another embodiment of the invention, the quality of the audioinformation contained in the at least one audio object is higher thanthe quality of the audio information contained in the at least one videoobject.

In still another embodiment of the invention, the reproduction mode canbe switched in accordance with an input by a user.

In still another embodiment of the Invention, the reproduction apparatusincludes a video output terminal. for outputting the video information,the reproduction mode being switched in accordance with the state ofconnection of the video output terminal.

In still another embodiment of the invention, the reproduction apparatusis a reproduction apparatus to be mounted in an automobile, thereproduction mode being switched in accordance with a state of motion ofthe automobile.

In another aspect of the present invention, there is provided a methodfor reproducing an optical disk in a reproduction mode, the optical diskincluding a data region and a management region, the data regionstoring: at least one video object containing video information andaudio information; and at least one audio object containing audioinformation, wherein the management region stores first path informationand second path information, the first path information indicating afirst reproduction path including only the at least one video object,and the second path information indicating a second reproduction pathincluding a combination of the at least one video object and the atleast one audio object, the reproduction method including the steps of:determining whether the reproduction mode is a first reproduction modefor reproducing video information and audio information or a secondreproduction mode for reproducing only audio information; andreproducing the video information and the audio information contained inthe at least one video object along the first reproduction path in thecase where the reproduction mode is the first reproduction mode, andreproducing the audio information contained in the at least one videoobject and the audio information contained in the at least one audioobject along the second reproduction path in the case where thereproduction mode is the second reproduction mode.

Thus, the invention described herein makes possible the advantages of(1) providing an optical disk capable of switching, in accordance withvarious modes of viewing/listening as desired by a user, betweenexclusive reproduction of audio information and reproduction of bothvideo information and audio information without the creation ofmalfunctions, as well as an apparatus and a method for reproducing suchan optical disk; and (2) providing an optical disk which allows thereproduction or playback of higher-quality audio information duringaudio reproduction than during video reproduction, as well as anapparatus and a method for reproducing such an optical disk.

These and other advantages of the present Invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view showing an optical disk according to anexample of the present invention.

FIG. 1B is a cross-sectional view of an optical disk according to anexample of the present invention.

FIG. 1C is an enlarged cross-sectional view of an optical disk accordingto an example of the present invention.

FIG. 1D is a diagram showing the shapes of pits formed on an opticaldisk according to an example of the present invention.

FIG. 2A is a diagram showing the track structure of an optical diskaccording to an example of the present invention.

FIG. 2B is a diagram showing the sector structure of an optical diskaccording to an example of the present invention.

FIG. 3 is a diagram showing the track structure of an optical diskaccording to an example of the present invention.

FIG. 4 is a diagram showing the data structure of a video title setaccording to an example of the present invention.

FIG. 5 is a diagram showing how a video menu according to an example ofthe present invention is displayed.

FIG. 6 is a diagram showing the data structure of a video title setaccording to an example of the present invention.

FIG. 7 is a diagram showing the data structure of a video manageraccording to an example of the present invention.

FIG. 8A is a diagram showing the data structure of an audio title set ofan AOB point type according to an example of the present invention.

FIG. 8B is a diagram showing the data structure of an audio title set ofa VOB point type according to an example of the present invention.

FIG. 8C is a diagram showing the data structure of ATS addressinformation of an ATS management table of an audio title set accordingto an example of the present invention.

FIG. 9 is a diagram showing the data structure of an audio manageraccording to an example of the present invention.

FIG. 10 is a perspective view showing a DVD player according to anexample of the present invention and a television monitor coupledthereto.

FIG. 11 is a view showing a remote control-according to an example ofthe present invention.

FIG. 12 is a block diagram showing the structure of a DVD player as adisk reproduction apparatus according to an example of the presentinvention.

FIG. 13A is a flowchart showing the flow of a reproduction process in avideo-oriented reproduction mode according to an example of the presentinvention.

FIG. 13B is a flowchart showing the flow of a process of reproducing atitle in a video-oriented reproduction mode according to an example ofthe present invention.

FIG. 14A is a flowchart showing the flow of a reproduction process in anaudio-oriented reproduction mode according to an example of the presentinvention.

FIG. 14B is a flowchart showing the flow of a process of reproducing atitle in an audio-oriented reproduction mode according to an example ofthe present invention.

FIG. 15 is a diagram showing how a start menu stored in a video manageraccording to an example of the present invention is displayed.

FIG. 16A is a diagram showing an exemplary structure of an applicationaccording to an example of the present invention.

FIG. 16B is a diagram illustrating the operation of a disk reproductionapparatus according to an example of the present invention.

FIG. 17 is a diagram showing the positions on an optical disk at whichvarious data are stored according to an example of the presentinvention.

FIG. 18 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 19 is a flowchart showing the flow of a reproduction process by anaudio player with video functions according to an example of the presentinvention.

FIG. 20A is a diagram showing a specific example of title searchpointers of audio manager information and video manager information ofan optical disk according to an example of the present invention.

FIG. 20B is a diagram showing a specific example of a PGC structure ofan ATS of the AOB point type of an optical disk according to an exampleof the present invention.

FIG. 20C is a diagram showing a specific example of a PGC structure ofan ATS of the VOB point type of an optical disk according to an exampleof the present invention.

FIG. 21A shows exemplary data to be stored on an optical disk accordingto an example of the present invention.

FIG. 21B is a diagram showing the reproduction order by a reproductionapparatus according to an example of the present invention.

FIG. 21C is a diagram showing the reproduction order by a reproductionapparatus according to an example of the present invention.

FIG. 22 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention in the case where PGC blocks are present.

FIG. 23A is a diagram showing a specific example of a title searchpointer table according to an example of the present invention.

FIG. 23B is a diagram showing a specific example of a PGC structure ofan ATS of the AOB point type according to an example of the presentinvention.

FIG. 23C is a diagram showing a specific example of a PGC structure ofan ATS of the VOB point type according to an example of the presentinvention.

FIG. 23D is a diagram showing a specific example of audio attributes ofan ATS management table according to an example of the presentinvention.

FIG. 23E is a diagram showing a specific example of audio attributes ofan ATS management table according to an example of the presentinvention.

FIG. 24A is a flowchart showing the flow of a process of reproducing atitle in an audio-oriented reproduction mode according to an example ofthe present invention in the case where PGC blocks are present.

FIG. 24B is a flowchart showing the flow of a process of selecting a PGCin a PGC block according to an example of the present invention.

FIG. 25 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 26 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 27 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 28 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 29 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 30 is a diagram schematically showing the relationship betweenvarious reproduced information and objects according to an example ofthe present invention.

FIG. 31 is a diagram showing the data structure of an audio manager forperforming automatic reproduction at the time of inserting a diskaccording to an example of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described by way of examples,with respect to the accompanying figures.

EXAMPLE 1

Hereinafter, the structure of an optical disk according to one exampleof the present invention will be described.

(1) Physical Structure of the Optical Disk

FIG. 1A is a perspective view showing a DVD 100, which is one type ofoptical disk. FIG. 1B is a cross-sectional view of the DVD 100 takenalong line A-A′ in FIG. 1A. FIG. 1C is an enlarged cross-sectional viewof portion B shown in FIG. 1B.

As shown in FIG. 1B, the DVD 100 is formed by laminating a. firsttransparent substrate 108, an information layer 109, an adhesive layer110, a second transparent substrate 111, and a print layer 112 (on whicha label is to be printed) in this order.

The first transparent substrate 108 and the second transparent substrate111 are reinforcement substrates that are formed of the same material.In the example shown in FIG. 1B, these substrates each have a thicknessof about 0.6 mm. These substrates can each have a thickness in the rangebetween about 0.5 mm and about 0.7 mm.

The adhesive layer 110 is provided between the information layer 109 andthe second transparent substrate 111, thereby adhering the informationlayer 109 to the second transparent substrate 111.

On the face of the information layer 109 in contact with the firsttransparent substrate 108 is formed a reflective film (not shown), whichis formed of a thin metal film or the like. By using a moldingtechnique, a high density of convex and concave pits are formed on thereflective film.

FIG. 1D shows the shapes of pits formed on the reflective film. In theexample shown in FIG. 1D, each pit has a length of 0.4 μm to 2.054 μm. Ahelical track is formed on the DVD 100. The pits are formed alongsidethe helical track so as to be at a distance of 0.74 μm from the helicaltrack along a radial direction of the DVD 100. Thus, an array of pitsare formed along the helical track.

As. shown in FIG. 1C, when a light beam 113 is radiated on the DVD 100,a light spot 114 is formed on the information layer 109. The informationstored on the DVD 100 is detected as variation in the reflectance of theportion of the information layer 109 which is illuminated by the lightspot 114.

The diameter of the light spot 114 of the DVD 100 is about 1/1.6 of thediameter of a light spot on a CD (compact disk) because the numericalaperture (NA) of an object lens for DVDs is larger then the numericalaperture (NA) of an object lens for CDs and because the. wavelength λ ofa light beam for DVDs is smaller than the wavelength λ of a light beamfor CDs.

A DVD having the above-described physical structure can store about 4.7Gbytes of information on one side. A storing capacity of about 4.7Gbytes is nearly 8 times the storing capacity of a conventional CD. Suchlarge storing capacity of DVDs makes it possible to greatly improve thequality of moving images. It is also possible to greatly improve thereproduction time length of moving images. In contrast to thereproduction time length of a conventional video CD being 74 minutes, aDVD boasts of a reproduction time length of 2 hours or more.

The fundamental technology which realizes such large storing capacitylies in reduction of the spot diameter D of the light beam. The spotdiameter D is calculated from the formula: Spot diameter D=Laserwavelength λ/ Numerical aperture NA of the object lens. Accordingly, thespot diameter D can be minimized by decreasing the laser wavelength λand increasing the numerical aperture NA of the object lens. It shouldbe noted, however, that increasing the numerical aperture NA of theobject lens can result in coma aberration due to the relative slant(i.e., “tilt”) between the disk surface and the optical axis of thelight beam. In the case of DVDs, the coma aberration is minimized byreducing the thickness of a transparent substrate. Reducing thethickness of a transparent substrate can result in a separate problem oflower mechanical strength of the disk. In the case of DVDs, the strengthof the transparent substrate is reinforced by attaching anothersubstrate to the transparent substrate, thereby overcoming the problemsassociated with the mechanical strength of the disk.

A red semiconductor. laser having a short wavelength of 650 nm and anobject lens having a large numerical aperture (NA) of about 0.6 mm areused to read out the information stored on a DVD. By employing these andadditionally a thin transparent substrate having a thickness of about0.6 mm, it is possible to store about 4.7 Gbytes of information on oneside of an optical disk having a diameter of 120 mm.

FIG. 2A schematically illustrates a helical track 20 being formed fromthe inner periphery toward the outer periphery of the information layer109 of the DVD 100. The helical track 20 is divided into predeterminedunits referred to as sectors. In FIG. 2A, the respective sectors aredenoted by numerals S1, S2, . . . , S99, and S100. The reading of theinformation stored on the DVD 100 is performed on a sector by sectorbasis.

FIG. 2B shows the internal structure of a sector, where the sectorincludes a sector header region 21, a user data region 22, and an errorcorrection code storage region 23.

The sector header region 21 stores a sector address for identifying thesector and an error detection code thereof. Based on these sectoraddresses, a disk reproduction apparatus will determine which one of aplurality of sectors information should be read from.

The user data region 22 stores a data string which is 2 Kbytes long.

The error correction code storage region 23 stores error correctioncodes for the sector header region 21 and the user data region 22 withinthe same sector. A disk reproduction apparatus will perform errordetection by using the error correction codes and performs errorcorrection based on the error detection results, thereby securingreliability of data reading.

(2) Logical Structure of the Optical Disk

FIG. 3 shows the logical structure of a DVD 100 as an optical disk. Asshown in FIG. 3, the regions of the DVD 100 are divided into a lead-inregion 31, a volume region 32, and a lead-out region 33. These regionscan be identified by the identification information included in thesector addresses of physical sectors. The physical sectors are arrayedin an ascending order based on their sector addresses.

In the lead-in region 31, data for stabilizing the operation of a diskreproduction apparatus at the beginning of a read and the like arestored.

No meaningful data is stored in the lead-out region 33. The lead-outregion 33 is used for Informing a disk reproduction apparatus of the endof reproduction.

The volume region 32 stores digital data corresponding to eachapplication. The physical sectors included in the volume region 32 aremanaged as logic blocks. The logic blocks are identified by thesequential numbers (logic block numbers) respectively assigned to thephysical sectors after the first physical sector (designated as the0^(th) physical sector) in the volume region 32. A portion 34 shown inFIG. 3 shows a group of logic blocks in the volume region 32. in theportion 34, #m, #m+1, #m+2, #m+3, . . . denote the logic block numbersassigned to the respective logic blocks.

As shown in FIG. 3, the volume region 32 is subdivided into a volumefile management region 32 a, a video zone region 32 b, and an audio zoneregion 32 c.

The volume file management region 32 a stores file system managementinformation for managing a plurality of logic blocks as files inaccordance with ISO13346. The file system management information isinformation indicating the correspondence between the name of each of aplurality of files and the addresses of the logic blocks occupied bythat file. A disk reproduction apparatus achieves file-by-file access tothe optical disk based on the file system management information.Specifically, the disk reproduction apparatus will refer to the filesystem management information to obtain the addresses of the logicblocks corresponding to a given file name, and accesses the logic blocksbased on these addresses. As a result, the digital data contained In thedesired files can be read out.

The video zone region 32 b stores video manager information 700 and oneor more video title sets 600.

A video title set 600 contains a plurality of video data and managementinformation for managing the order of reproducing the plurality of videodata. The video title set 600 has a data structure that allowsmanagement of the video data in units which are referred to as videotitles. For example, if the video title set 600 is a video application,the video titles may correspond to a plurality of video versions, e.g.,a theatrical version, non-abridged version, and the like. The specificdata structure of the video title set 600 will be described later withreference to FIG. 6.

The video manager information 700 contains information representing atable of contents consisting of a plurality of video title sets 600.Typically, the video manager information 700 includes informationrequired for displaying a video menu for allowing a user to select adesired one of a plurality of video title sets 600 and the managementinformation thereof. The specific data structure of the video managerinformation 700 will be described later with reference to FIG. 7.

The audio zone region 32 c stores audio manager information 900 and oneor more audio title sets 800.

The audio title set 800 contains a plurality of audio data andmanagement information for managing the order of reproducing theplurality of audio data. The audio title set 800 has a data structurethat allows management of the audio data in units which are referred toas audio titles. Typically, an audio title corresponds to a music albumcontaining one or more songs. The audio title set 800 can also containmanagement information defining the order of reproducing the video datacontained in the video title set 600. The specific data structure of theaudio title set 800 will be described later with reference to FIGS. 8Aand 8D.

The audio manager information 900 contains information representing atable of contents consisting of a plurality of audio title sets 800. Thespecific data structure of the audio manager information 900 will bedescribed later with reference to FIG. 9.

In FIG. 3, the video title set 600 and the audio title set 800 are eachillustrated as one file. In practice, however, the video title set 600or the audio title set 800 is very often composed of a plurality ofconsecutive files because moving image data has such an enormous datasize that trying to accommodate the entire moving image data into onefile may result in a file size of more than 1 GB.

(3) Data Structure of the Video Zone Region 32 b (FIG. 3)

The video zone region 32 b stores video manager information 700 and oneor more video title sets 600.

(3.1) Data Structure of the Video Title Set 600

FIG. 4 shows the data structure of the video title set 600. The videotitle set 600 includes a plurality of video objects (hereinafterreferred to as “VOB”) 602 and video title set information 601 formanaging the order of reproducing a plurality of VOBs 602.

In the discussions to follow, a “video title set” may occasionally bereferred to as “VTS”.

(3.1.1) Data Structure of the VOB 602

A VOB 602 is a piece of multimedia data. A VOB 602 contains digitalmoving image data, digital audio data, sub-picture data, and managementinformation for the management thereof.

The VOBs 602 have a data structure in accordance with MPEG2 (MovingPicture Expert Group, ISO11172, ISO13818), and are referred to as MPEG2stream data. A VOB 602 includes a plurality of VOB units (hereinafterreferred to as “VOBUs”) 603 which are arranged in a chronological order.A VOBU 603 is a reproduction data running about 0.4 seconds to about 1.0second, and includes a plurality of kinds of pack data 604 (e.g.,management information packs, moving image packs, audio packs, and/orsub-picture packs), as indicated ahead of the arrows in FIG. 4. In theexample illustrated in FIG. 4, the management information packs aredenoted by numerals such as P1 and P2; moving image packs are denoted bynumerals such as video 1, video 2, video 3, and video 4; audio packs aredenoted by numerals such as audio A-1, audio B-1, audio C-1, audio A-2,audio B-2, and audio C-2; sub-picture packs are denoted by numerals suchas SP A-1, SP B-1, SP A-2, and SP B-2.

Each pack data has a data size of 2 Kbytes. By reorganizing a pluralityof pack data belonging to each kind of data, a digital data sequenceonly containing is moving image data, a digital data sequence onlycontaining audio data, a digital data sequence only containingsub-picture data, or a digital data sequence only containing controldata can be obtained. A digital data sequence obtained by thusreorganizing a plurality of pack data belonging to one kind of data isreferred to as an elementary stream.

A VOB 602 may also be referred to as a program stream or system streamcontaining a plurality of elementary streams. One VOB 602 can includeone moving image elementary stream, up to 8 audio elementary streams,and up to 32 sub-picture elementary streams. A moving image elementarystream may be referred to as a main stream of a system stream, while anaudio elementary stream and a sub-picture elementary stream may bereferred to as sub-streams of the system stream.

The pack data includes a header section and a data section. The headersection of a pack data stores identification information for indicatingthe kind of that pack data. By referring to the identification data, itis possible to identify the pack data as a “moving image pack”, an“audio pack”, a “sub-picture pack”, or a “management information pack”.

The data section of a moving image pack stores data which is compressedin accordance with the MPEG method. One VOBU 603 stores moving imagedata in a GOP-by-GOP manner. A GOP (group of pictures) is defined asimage data equivalent to about 12 to 15 frames.

The data section of an audio pack stores audio data corresponding to themoving image data in A VOBU 603 which contains that audio pack. Themoving image data and the audio data contained in the same VOBU 603 arereproduced in synchronization. Examples of audio data include linear PCMdata or Dolby-AC3 data (see ATSC standard Digital audio Compression(AC-3)(Doc.A/52,20 December, 1995). The header section of an audio packfurther stores audio sub-stream identification information indicatingwhich one of 8 or less audio sub-streams the audio pack belongs to.

The data section of a sub-picture pack stores graphics data which hasbeen subjected to run length compression. The header section of asub-picture pack further stores sub-picture sub-stream identificationinformation indicating which one of 32 or less sub-picture sub-streamsthe sub-picture pack belongs to.

The data section of a management information pack stores addressinformation for trick play modes (e.g., high-speed playback) and controldata for accepting user interactions. One example of control data foraccepting user interactions is menu information for displaying a menu.The menu information includes information indicating the positions of upto 32 menu items, information indicating the colors of the menu items,and information indicating a control command to be executed when one ofthe menu items is selected by a user.

FIG. 5 shows an exemplary menu. In the example illustrated in FIG. 5,the menu 50 has 8 menu items 51 to 58 respectively representing theinformation to be reproduced next. For each of the 8 menu items 51 to58, the menu information defines its position and color, as well as acontrol command to be executed when that menu item is selected. One ofthe 8 menu items 51 to 58 is to be selected by a user.

The graphics data for displaying a menu is stored In a sub-picture pack.When a user selects one of the plurality of menu items or confirms sucha selected menu item, the color of a graphic corresponding to theselected menu item is changed in accordance with the positioninformation and color information in the management information pack.

When a user confirms A selected menu item, a control command associatedwith that menu item is executed. Thus, a diversified reproductioncontrol is realized in accordance with instructions from a user.

For conciseness, the pack data included in the VOBUs 603 are shown to bearranged with some regularity in the example of FIG. 4. However, thepack data need not be arranged with any regularity except that themanagement information pack needs to be located at the beginning of eachVOBU 603. For example, the pack data need not be arranged so as to formbundles each containing only one kind of pack data. Rather, the packdata may be shuffled or arranged irrespective of the kinds of pack data,because a disk reproduction apparatus will first buffer the pack datainto a buffer section and then read out the pack data from the buffersection. The total number of pack data included in each VOBU 603 and/orthe number of pack date of each kind need not be a constant numberbecause the moving image data, audio data, and/or sub-picture data maybe variable-length compressed data. In practice, each VOBU 603 willinclude a different number of pack data.

Two moving image packs are shown to be included in the exemplary VOBU603 of FIG. 4. However, the number of moving image packs included in anactual VOBU 603 can be on the order of several hundred because thetransfer rate of moving image data to a disk reproduction apparatus isabout 4.5 Mbits.

(3.1.2) Data Structure of the Video Title Set Information 601

The video title set information 601 includes information for managingthe order of reproducing the VOBs 602. Herein, the data which designatesthe order of reproducing the VOBs 602 is referred to as a program chain(PGC). Different PGCs can define different orders by which the VOBs 602are reproduced.

FIG. 6 shows the data structure of the video title set information 601.As shown in FIG. 6, the video title set information (VTSI) 601 includesa VTS management table (VTSI_MAT) 611, a video title set section titlesearch pointer table (TT_SRPT) 612, and a PGC management informationtable (PGCIT) 613.

The VTS management table 611 serves as header information of the videotitle set information 601. The VTS management table 611 includes apointer indicating the position at which the video title set sectiontitle search pointer table 612 is stored and a pointer indicating theposition at which the PGC management information table 613 is stored.

The video title set section title search pointer table 612 includes thenumber of pointers 621 and a plurality of start PGC numbers 622. A startPGC number 622 is an index indicating the PGC information 631 to beexecuted first among the plurality of PGC information units 631 storedin the PGC management information table 613. A start PGC number 622 isdesignated for each title. For example, if the value of the start PGCnumber 622 corresponding to title#1 is “3”, it indicates that PGCinformation#3 is to be executed first for title#1.

The FGC management information table 613 includes a plurality of PGCinformation units 631 (i.e., PGC information#1 to PGC information#n).The PGC information 631 defines the position at which one or more VOBs602 are stored on the disk and the order of reproducing such VOBs 602.It is possible for different PGC information units 631 to describe thereproduction of the same VOBs 602. Therefore, it is possible todesignate a plurality of reproduction orders for the same VOBs 602. Forexample, if the PGC information 631 defines reproduction of VOBs 602 inthe order of VOB#1, VOB#2, VOB#3, and VOB#4, the VOBs 602 will bereproduced in the order of VOB#1, VOB#2, VOB#3, and VOB#4. If the PGCinformation 631 defines reproduction of VOBs 602 in the order of VOB#3,VOB#2, VOB#1, and VOB#4, the VOBs 602 will be reproduced in the order ofVOB#3, VOB#2, VOB#1, and VOB#4.

The PGC information 631 includes FGC connection information 641 and oneor more VOB addresses 642.

The PGC connection information 641 stores the indices of the FGCinformation units 631 to be jointed before and after the PGC information631. For example, the PGC connection information 641 of PGCinformation#3 stores the index of the PGC information 631 (e.g., PGCinformation#1) to be jointed before PGC information#3 and the index ofthe PGC information 631 (e.g., PGC information#5) to be jointed afterPGC information#3. Once the reproduction of one PGC information 631 iscomplete, a disk reproduction apparatus determines. the next PGCinformation 631 in accordance with the PGC connection information 641and continues the reproduction control in accordance with the next PGCinformation 631.

The VOB address 642 Is information indicating the position (on theoptical disk) of the VOB 602 to be reproduced. The order of the VOBaddresses 642 within the PGC information 631 represents the order bywhich the VOBs 602 are reproduced by a disk reproduction apparatus.

(3.2) Data Structure of the Video Manager Information 700

The video manager information 700 is information for reproductioncontrol that is to be first referred to when the optical disk isreproduced by a disk reproduction apparatus in a video-oriented manner.

FIG. 7 shows the data structure of the video manager information 700.

The data structure of the video manager information 700 is in compliancewith the data structure of the video title set 600 shown in FIG. 6. Thedifference between the VOBs of the video manager information 700 and theVOBs of the video title set 600 is that the VOBs of the video managerinformation 700 are specialized for volume menus.

Herein, a “volume menu” is defined as a menu for displaying all of thetitles stored on an optical disk to allow a user to select one of thetitles. A volume menu is displayed on screen immediately after anoptical pickup has moved from the volume file management region 32 a tothe video zone region 32 b of the optical disk, following loading of theoptical disk into a disk reproduction apparatus.

As shown in FIG. 7, the video manager information (VMGI) 700 includesvideo object 703 for a menu, a PGC management information table (PGCIT)701 for a menu, and a title search pointer table (TT_SRPT) 702.

The video object 703 for a menu is, as its name indicates, a VOB whichis specialized for use in a volume menu. The video object 703 for a menuincludes a sub-picture pack for displaying a volume menu and amanagement information pack for performing a reproduction control inresponse to a cursor manipulation and/or confirmation operation for thevolume menu.

The PGC management information table 701 for a menu is PGC informationwhich is specialized for use in a volume file. in the PGC managementinformation table for a menu 701, the position at which the video object703 for a menu is stored is described so that the video object 703 for amenu will be read when the optical disk is loaded in a disk reproductionapparatus. This PGC information is read immediately after an opticalpickup has moved from the volume file management region 32 a to thevideo zone region 32 b, following loading of the optical disk into adisk reproduction apparatus. As a result, a volume menu is displayed onscreen.

The title search pointer table 702 includes the number (i.e., a VTSnumber 721) of the video title set to which each title belongs and anindex 712 for specifying the title number (i.e., an intra-VTS titlenumber 722) assigned to each title within that video title set.

(4) Data Structure of the Audio Zone Region 32 c

The audio zone region 32 a stores audio manager information 900 and oneor more audio title sets 800.

(4.1) Data Structure of the Audio Title Set 800

FIG. 8A shows the data structure of the audio title set 800. The audiotitle set 800 includes a plurality of audio objects (hereinafterreferred to as “AOBs”) 802, audio title set information (ATSI) 801 formanaging the order of reproducing a plurality of AOBs 802, and audiotitle set information backup (ATSI_BUP) 804 (which is backup data of theaudio title set information 801).

In the discussions to follow, an “audio title set” may occasionally bereferred to as “ATS”.

(4.1.1) Data Structure of the AOB 802

The AOB 802 is grouped into packets of 2 Kbytes. The AOB 802 stores datain the LPCM formats AC3 format, MPEG Audio format (see ISO/IEC DIS13818-3: July, 1996), DTS format (see DTS Coherent Acoustics “Deliveringhigh quality multichannel sound to the consumer” presented at the100^(th) Convention, May 11-14, 1996 Copenhagen AES) or SDDS format (seeSDDS Specification for Diso (Version 1.0)-Digital audio multi-channelcoding, Sony Corporation). In the case of LFCM, the sample bit is 16,20, or 24 bits, with a sampling frequency of 48 kHz, 96 kHz, 192 kHz,44.1 kHz, 88.2 kHz, or 176.4 kHz.

(4.1.2) Data Structure of the Audio Title Set Information 801

The audio title set information (ATSI) 801 includes information formanaging the order of reproducing the AOBs 802. The order of reproducingthe AOBs 802 is designated by a program chain (PGC), as in the case ofVOBs 602. Different PGCs can define different orders by which the AOBs802 are reproduced.

As shown in FIG. 8A, the audio title set information (ATSI) 801 includesan ATS management table (ATSI_MAT) 811 and an ATS program chaininformation table (ATS_PGCXT) 812.

The ATS management table 811 serves as header Information of the audiotitle set information 801. The ATS management table 811 includes apointer indicating the region in which the ATS program chain informationtable 812 is stored and a pointer indicating the region in which the AOB802 is stored.

The ATS management table 811 includes an ATS identifier (ATSI_ID) 821,ATS address information 822, an ATS version number 823, audio attributes(AOTT_AOB_ATR) 824, and a downmix factor 825.

The ATS identifier 821 stores a string of letters indicating the titleset being an ATS.

The ATS address information 822 will be described later.

The ATS version number 823 stores the version number of the standarddefining the data structure of the audio title set information 801.

The audio attributes 824 store 8 kinds of audio stream attributes. EachAOB 802 included in an audio title set 800 is to be reproduced inaccordance with one of the 8 kinds of audio stream attributes. The audioattributes 824 include an audio coding mode 841, a quantization bitnumber 842, a sampling frequency 843, and a multi CH (channel) attribute844.

The audio coding mode 841 describes a code representing LPCM or acompression method. The quantization bit number 842 describes a coderepresenting 16, 20, or 24 bits. The sampling frequency 843 describes acode representing 48 kHz, 96 kHz, 192 kHz, 44.1 kHz, 88.2 kHz, or 176.4kHz. The multi CH attribute 844 describes a code representing, forexample, how to use each channel in the case of a multi CH system. . Anyunused field in the audio attributes 824 stores the value “0”.

The downmix factor 825 stores 16 kinds of factors to be used indownmixing the respective channels of a multi CH system into 2 CH. Oneof the 16 kinds of factors stored in the downmix factor 825 isselectively referred to by ATS program Information (ATS_PGI) 862 ofprogram chain information (ATS_PGCI) 833 (described later). Thus, thedownmix factor can be changed from program to program.

As shown in FIG. 8A, the ATS program chain information table 812includes ATS program chain information table information (ATS_PGCITI)831, a plurality of ATS program chain information search pointers(ATS_PGCI_SRP) 832, and a plurality of ATS program chain information(ATS_PGCI) units 833.

The ATS program chain information table information 831 describes thenumber of ATS program chain information search pointers 832, and thelast address of the ATS program chain information table 812. The ATSprogram chain information table information 831 is used for assisting inthe search of the ATS program chain information search pointers 832.

Each ATS program chain information search pointer 832 includes ATS_PGCcategory (ATS_PGC_CAT) 851 describing the title numbers within the ATSand the category of the PGC, and an ATS_PGC start address (ATS_PGCI_SA)852 indicating the position at which the ATS program chain informationIs stored.

The ATS program chain information 833 includes ATS_PGC generalinformation (ATS_PGC_GI) 861 (including the playback (reproduction) timeand address information concerning this program chain), a plurality ofATS cell playback (reproduction) information units (ATS_C_PBI) 863(including the addresses and attributes of cells, which are minimalreproduction units of an AOB 802), and a plurality of ATS programinformation units (ATS_PGI) 862.

Each of the plurality of ATS program information units 862 includes astream number 881, a downmix factor number 882 indicating the number ofthe downmix factor (i.e, index for one of the 16 kinds of factorsincluded in the downmix factor 825 of the ATS management table 811) usedwhen downmixing multi CH into 2 CH, an entry cell number (ATS_PG_EN_CN)883 indicating the ATS cell number to be reproduced first among theplurality of ATS cells included in the program, and PG (program)playback time (ATS_PG_PB_TM) 884.

The stream number 881 is a number for specifying one of the 8 kinds ofaudio stream attributes defined by the audio attributes 824 of the ATSmanagement table 811. The audio stream is reproduced in accordance withthe audio attributes 824 specified by the stream number 881. Thus, anaudio stream can be, reproduced in accordance with different audioattributes, depending on the program.

Thus, the ATS program chain information 833 describes the position (onthe disk) at which one or more AOBs 802 are stored and the order ofreproducing the AOBs 802. It is possible for different ATS program chaininformation units 833 to describe the reproduction of the same AOBs 802.Therefore, it is possible to designate a plurality of reproductionorders for the same AOBs 802. For example, if ATS program chaininformation unit 833 defines reproduction of AOBs 802 in the order ofAOB#1, AOB#2, AOB#3, and AOB#4, the AOBs 802 will be reproduced in theorder of AOB#1, AOB#2, AOB#3, and AOB#4. If the ATS program chaininformation unit 833 defines reproduction of AOBs 802 in the order ofAOB#3, AOB#2, AOB#1, and AOB#4, the AOBs 802 will be reproduced in theorder of AOB#3, AOB#2, AOB#1, and AOB#4.

The audio title sets 800 can be classified into those which point toAOBs 802 (“AOB point type”) and those which point to VOBs 602 (“VOBpoint type”) instead of AOBs 802. The data structure shown in FIG. 8A isthe data structure of an audio title set 800 of an AOB point type.

FIG. 8B shows the data structure of an audio title set 800 of the VOBpoint type. The data structure shown in FIG. 8D is identical with thedata structure shown in FIG. 8A except that the audio title set 800 ofFIG. 8B does not include a plurality of AOBs 802. Moreover, therespective attribute information units include descriptions which arespecific to VOBs 602.

Specifically, the address information of the VTS 600 to which the VOB602 belongs and the address information of the VOB 602 are described inthe ATS address information 822 of the ATS management table 811. In theaudio attributes 824 of the ATS management table 811, the description ofa stream ID 845 for specifying which one of the sub-streams included inthe VTS 600 is to be reproduced is additionally included as well as theaudio attributes defined in the VOB 602. The sampling frequency 843 ofthe audio attributes 824 is limited to either 48 kHz or 96 kHz. A coderepresenting LPCM, AC3, MPEG Audio, DTS or SDDS can be described in theaudio coding mode 841. The downmix factor 825 of the ATS managementtable 811 is filled with “0”s, indicating that the downmix factor 825 isnot used.

An audio coding mode 875 of the ATS_PGC category 851 describes a codedefined in the VOB 602.

An ATS cell start address (ATS_C_SA) 893 and an ATS call end address(ATS_C_EA) 894 of the ATS cell playback information 863 describe theaddress of a cell of a VOB 602.

FIG. 8C shows the data structure of the ATS address information 822.

The ATS address Information 822 Includes the last address 822 a of theaudio title set 800, the last address 822 b of the audio title setinformation 801, the last address 822 c of the ATS management table 811,the start address 822 d of a video title set 600, the start address 822e of an object region, and the start address 822 f of the ATS programchain information table 812. In FIG. 8C, the arrows from the ATS addressinformation 822 represent the locations to which the respectiveaddresses point.

In the case where the audio title set 800 is of an AOB point type (FIG.8A), the start address 822 d of the video title set 600 of the ATSaddress information 822 is filled with “0”s. In the case where the audiotitle set 800 Is of a VOB point type (FIG. 8B), the start address 822 dof the video title set 600 stores the start address of the video titleset 600 to which VOBs 602 belong. Therefore, the.audio title set 800 isof an AOB point type if the value “0” is stored in the field 822 d ofthe ATS address information 822; otherwise the audio title set 800 is ofa VOB point type.

Thus, an audio title set 800 can be identified as either an AOB pointtype or a VOB point type by referring to the field 822 d of the ATSaddress information 822.

In the case where the audio title set 800 is of an AOB point type, thestart address of AOB#1 is stored in the start address 822 e of an objectregion. In the case where the audio title set 800 is of a VOB pointtype, the start address of VOB#1 is stored in the start address 822 e ofan object region.

Thus, the reproduction order of AOBs 802 or VOBs 602 can be determinedbased on an audio title set as one unit.

(4.2) Data Structure of the Audio Manager Information 900

The audio manager information 900 is information for reproductioncontrol that is to be referred to first when the optical disk isreproduced by a disk reproduction apparatus in an audio-oriented manner.

FIG. 9 shows the data structure of the audio manager information 900.

The audio manager information (AMGI) 900 includes an audio managerInformation management table (AMGI_MAT) 901, an audio title searchpointer table (ATT_SRPT) 902, an audio-only title search pointer table(AOTT_SRPT) 903, an audio manager menu PGC management information table(AMGM_PGCI_UT) 904, and an audio text data manager (ATXTDT_MG) 905.

The audio manager information management table 901 stores the attributesof the audio manager information 900, the address information of varioustables, and the like.

The audio title search pointer table 902 includes audio title searchpointer table information (ATT_SRPTI) 911 and a plurality of audio titlesearch pointers (ATT_SRP) 912.

The audio title search pointer table information 911 stores the numberof audio titles and the last address of the audio title search pointertable 902.

The audio title search pointer 912 stores different kinds of informationdepending on whether to designate the title of an ATS or the title of anVTS. When designating the title of an ATS, the audio title searchpointer 912 stores an ATS number 934, an intra-ATS title number 935, andan ATS start address 936. When designating the title of a VTS, the audiotitle search pointer 912 stores a VTS number 942, an intra-ATS titlenumber 943, a VTS start address 944, and an angle number 941.

An audio title category 931 of the audio title search pointer 912includes an AOTT/AVTT flag 961, a menu regression flag 962, and an ATTgroup number 963.

When designating the title of an ATS, the AOTT/AVTT flag 961 stores acode representing AOTT. When designating the title of a VTS, theAOTT/AVTT flag 961 stores a code representing AVTT. the menu regressionflag 962 stores a flag indicating whether or not to return to a menuafter the reproduction of a designated title.

The ATT group number 963 stores the number of a title group to which thedesignated title belongs. Herein, a title group is defined as a conceptunder which it is ensured that a plurality of titles belonging to thesame title group are consecutively reproduced. The ATT group number 963is provided in order to allow consecutive reproduction of a plurality oftitles without performing a reproduction control based on complicatednavigation information.

The audio title search pointer table 902 is referred to by an audioplayer having a video function.

The audio-only title search pointer table 903 has a data structuresimilar to that of the audio title search pointer table 902. However,the title of a VTS is never designated by using an audio-only titlesearch pointer table 903.

The audio-only title search pointer table 903 is referred to by an audioplayer having only an audio output.

The audio manager menu PGC management information. table 904 describesthe reproduction order of menus.

The audio text data manager 905 stores information for displaying textinformation.

Hereinafter, a disk reproduction apparatus for reproducing theinformation stored on the DVD 100 will be described.

FIG. 10 shows a DVD player 1 as a reproduction apparatus for the DVD100, a television monitor 2 coupled to DVD player 1, and a remotecontrol 91.

The DVD player 1 has an opening in the front face of its body. A drivemechanism (not shown) for loading the DVD 100 is provided along thedepth direction of the opening.

In the front face of the DVD player 1 is provided a remote controlreception section 92 having a photosensitive element for receivinginfrared rays from the remote control 91. As a user operates on the keysof the remote control 91, an infrared ray which is in accordance withthe key input by the user is generated from the remote control 91. Inresponse to a received infrared ray, the remote control receptionsection 92 generates an interrupt signal indicative of the reception ofa key signal from the remote control 91.

In the back face of the DVD player 1 are provided a video outputterminal 95 and an audio output terminal 96. By connecting an AV(audio-visual) cord to these output terminals, a video signal which isreproduced from the DVD 100 can be output on the large televisionmonitor 2 for in-home use. Thus, a user can enjoy the images reproducedfrom the DVD 100 by employing a relatively large television for in-homeuse, e.g., 33 inches, 35 inches or the like.

As will be appreciated from the above description, the DVD player 1 isnot to be used while being connected to a computer apparatus such as apersonal computer, but is used as a home electric appliance while beingconnected to the television monitor 2.

The remote control 91 includes a plurality of keys on an operation panelon its body surface, the keys being energized with springs. Thus, theremote control outputs a code corresponding to a pressed key in the formof an infrared ray.

FIG. 11 shows the operation panel 91 a of the remote control 91. Variousoperation keys are provided on the operation panel 91 a:

A “POWER” key 192 is used turn the power of the DVD player 1 ON or OFF.

An “A-MODE” key 193 is used to designate an audio-oriented reproductionmode. When the “A-MODE” key 193 is pressed, the remote control 91transfers a code representing an audio-oriented reproduction mode to theDVD player 1.

A “V-MODE” key 194 is used to designate a video-oriented reproductionmode. When the “V-MODE” key 194 is pressed, the remote control 91transfers a code representing a video-oriented reproduction mode to theDVD player 1.

A “MENU” key 195 is used to call up a volume menu of the DVD 100 duringthe reproduction of video information or audio Information in accordancewith a program chain.

Ten keys 197 are used to give Instructions such as a chapter jump in thecase of a movie, or selection of a song in the case of music.

Cursor keys 198 are used to move a cursor in an up, down, right, or leftdirection to select an item.

An “ENTER” key 196 is used to confirm the item which has been selectedby the cursor. When the cursor is on an item, that item is displayed ina “selected” color as designated by the item color information of themanagement information pack. Once the selection of an item is confirmedby pressing the “ENTER” key 196, the item is displayed in a “confirmed”color as designated by the item color information of the managementinformation pack.

Keys 199 are used to give instructions such as “play”, “stop”, “pause”,“fast forward”, “rewind”, and the like to the DVD player 1. The keys 199Are commonly used on other AV apparatuses as well.

FIG. 12 shows the structure of the DVD player 1 according to an exampleof the present invention. As shown in FIG. 12, the DVD player 1 includesa drive mechanism section 16, a signal processing section 84, an AVdecoder section 85, an audio decoder section 94, a remote controlreception section 92 for receiving signals from the remote control 91,and a system control section 93.

The drive mechanism section 16 includes a base (not shown) on which theDVD 100 is to be set, and a motor 81 for clamping and rotating the DVD100 which has been set on the base. The motor 81 can be a spindle motor,for example. When setting the DVD 100, the DVD 100 is moved into/out ofthe body by means of an eject mechanism (not shown). A user sets the DVD100 on the base, with the base having been moved out of the body.Thereafter, the base on which the DVD 100 has been set is moved into thebody. Thus, the DVD 100 is loaded in the DVD player 1.

The drive mechanism section 16 further includes a mechanism controlsection 83 for controlling a mechanism system including the motor 81 andan optical pickup 82. The optical pickup 82 reads signals which arestored on the DVD 100.

The mechanism control section 83 adjusts the speed of the motor 81 inaccordance with the track position instructed from the system controlsection 93. The mechanism control section 83 controls the travel of theoptical pickup 82 by controlling an actuator (not shown) of the opticalpickup 82. Once the precise position of a track is detected throughservo control, the mechanism control section 83 waits for rotation untilreaching a position at which the desired physical sector is stored, andreads signals from the desired physical sector in a consecutive manner.

The signal processing section 84 performs processes, e.g.,amplification, waveform shaping, digitalization, decoding, and errorcorrection to the signal which has been read by means of the opticalpickup 82. The signal which has been read from the optical pickup 82 isconverted into digital data, and stored in a buffer memory 93 a in thesystem control section 93 in a logic-block-by-logic-block manner.

The AV decoder section 85 performs predetermined processes to the inputdigital data of VOBs 602 and converts the digital data into a videosignal and an audio signal. The video signal and the audio signal areoutput from the AV decoder 85.

The AV decoder section 85 includes a system decoder section 86, a videodecoder 87, a sub-picture decoder 88, an audio decoder 89 for an AVdecoder, and an image synthesis section 90.

The system decoder section 86 receives the digital data which istransferred from the buffer memory 93 a of the system control section 93in a logic-block-by-logic-block (i.e., packet by packet) manner, anddetermines the stream ID and sub-stream ID in the header of each packet,thereby classifying the packs into moving image data packs, sub-picturedata packs, audio data packs, and management information packs. Duringthis classification, the moving image data packs are output to the videodecoder 87. As for the sub-picture data packs and the audio data packs,only the sub-picture data packs and the audio data packs that have adesignated stream number are output to the sub-picture decoder 88 andthe audio decoder 89 for an AV decoder in accordance with a decodestream designation instruction which is input from the system controlsection 93. The management information packs are output to the systemcontrol section 93.

The moving image data packs which are input to the video decoder 87 areexpanded by a predetermined method in accordance with MPEG2, and outputto the image synthesis section 90 in the form of digital video data.

The sub-picture packs which are input to the sub-picture decoder 88 areexpanded by the run length method, and output to the image synthesissection 90 in the form of digital video data.

After being subjected to image synthesis by the image synthesis section90, the digital video data output from the video decoder 87 and thedigital video data output from the sub-picture decoder 88 are convertedinto a video signal in accordance with the NTSC method. The video signalis output to the exterior of the DVD player 1 via the video outputterminal 95 (FIG. 10).

The audio data packs which are input to the audio decoder 89 for an AVdecoder are decoded in accordance with the compression audio method(e.g., LPCM or AC3) depending on their data type, and subjected to a D/Aconversion, whereby an audio signal is obtained. The audio signal isoutput to the exterior of the DVD player 1 via the audio output terminal96 (FIG. 10).

The audio decoder section 94 performs predetermined processes for theinput digital data of AOBs 802 depending on their data type, whereby anaudio signal is obtained. The audio signal is output to the exterior ofthe DVD player 1 via the audio output terminal 96 (FIG. 10).

The system control section 93 includes a CPU 93 b for controlling theentire DVD player 1 and various work memories.

Next, the operation of the DVD player 1 having the above-describedstructure will be described.

As the “V-MODE” key 193 on the remote control 91 is pressed by a user,an infrared signal representing a video-oriented reproduction mode istransmitted from the remote control 91 to the DVD player 1. The infraredsignal from the remote control 91 is received and analyzed by the remotecontrol reception section 92 of the DVD player 1. As a result, a coderepresenting a video-oriented reproduction mode is retained in areproduction mode retention section 93 c within the system controlsection 93.

Similarly, as the “A-MODE” key 194 of the remote control 91 is pressedby a user, a code representing an audio-oriented reproduction mode isretained in the reproduction mode retention section 93 c in the systemcontrol section 93.

The system control section 93 includes a reproduction mode determinationsection 93 d. At the beginning of reproduction of the DVD 100, thereproduction mode determination section 93 d determines whether thereproduction mode is a video-oriented reproduction mode or anaudio-oriented reproduction mode by referring to the mode retained inthe reproduction mode retention section 93 c. The function of thereproduction mode determination section 93 d can be realized by, forexample, a program executed by the CPU 93 b.

It should be noted that the above-discussed reproduction mode is notalways switched in response to an input from a user.

For example, in the case where the disk reproduction apparatus is aportable device having a liquid crystal display panel which can beopened or closed, the reproduction mode may be automatically switched inaccordance with the open or closed state of the liquid crystal displaypanel. For example, if the liquid crystal display panel is in the openstate, the reproduction mode may be switched to a video-orientedreproduction mode; conversely, if the liquid crystal display panel is inthe closed state, the reproduction mode may be switched to anaudio-oriented reproduction mode. Such control can be achieved byinputting a control signal indicating the open or closed state of theliquid crystal display panel to the reproduction mode determinationsection 93 d so as to allow the reproduction mode determination section93 d to operate in response to that control signal.

Alternatively, the reproduction mode may be automatically switched inaccordance with the connection of the video output terminal. Forexample, if an AV cord is connected to the video output terminal, thereproduction mode may be switched to a video-oriented reproduction mode;conversely, if an AV cord is not connected to the video output terminal,the reproduction mode may be switched to an audio-oriented reproductionmode. Such control can be achieved by inputting a control signalindicating the state of connection of the video output terminal to thereproduction mode determination section 93 d so as to allow thereproduction mode determination section 93 d to operate in response tothat control signal.

Alternatively, the reproduction mode may be automatically switched inaccordance with the presence/absence of a video signal. For example, ifa video signal is output to the video output terminal, the reproductionmode may be switched to a video-oriented reproduction mode; conversely,if a video signal is not output to the video output terminal, thereproduction mode may be switched to an audio-oriented reproductionmode. Such control can be achieved by detecting the presence/absence ofa video signal and inputting a control signal indicating the detectionresult to the reproduction mode determination section 93 d so as toallow the reproduction mode determination section 93 d to operate inaccordance with that control signal.

Alternatively, in the case where the disk reproduction apparatus is adevice to be mounted in an automobile, the reproduction mode may beautomatically switched in accordance with the state of motion of theautomobile. For example, if the automobile is not moving, thereproduction mode may be switched to a video-oriented reproduction mode;conversely, if the automobile is moving, the reproduction mode may beswitched to an audio-oriented reproduction mode. Such control can beachieved by inputting a control signal indicating the state of motion ofthe automobile to the reproduction mode determination section 93 d so asto allow the reproduction mode determination section 93 d to operate inaccordance with that control signal. It can be detected whether or notan automobile is at rest by detecting, for example, the state of theparking brake or gearshift. In the case of an automatic transmissioncar, the gearshift being in the parking position will indicate that thecar is stopped.

FIG. 13A shows the flow of a reproduction process in the video-orientedreproduction mode. It is assumed herein that the reproduction mode hasalready been determined as the video-oriented reproduction mode.

At step S131, It Is determined whether or not an optical disk is loadedin the DVD player 1. Such determination can be performed by, forexample, the system control section 93 In accordance with a signal fromthe optical sensor.

If it is determined that an optical disk is loaded in the DVD player 1,the system control section 93 controls the rotation of the disk bycontrolling the mechanism control section 83 and the signal processingsection 84, and performs an initialization operation for causing theoptical pickup 82 to seek into the lead-in region 31 (FIG. 3). Thus, thereproduction process is started.

At step S132, the video manager Information 700 (FIG. 3) is read fromthe video zone region 32 b (FIG. 3). This reading Is performed based onthe information which is read from the volume file management region 32a (FIG. 3).

By referring to the PGC management information table for a menu 701 ofthe video manager information 700 (FIG. 7) (Step S133), the systemcontrol section 93 calculates the address of the program chaininformation for a volume menu (step S134), and reads the program chaininformation for the volume menu based on that address, and retains theprogram chain information for the volume menu within the system controlsection 93 (step S135).

By referring to the retained program chain information for the volumemenu, the system control section 93 calculates the address of the VOB703 (FIG. 7) for the menu that is to be reproduced first (step S136),and reproduces the VOB 703 for a menu based on that address (step S137).As a result, a video menu is displayed (step S138). The video menu isused by a user to select the title that the user wishes to reproduce.

FIG. 15 shows an exemplary displayed image of a video menu, where theuser can select a desired title from among “Movie A”, “Movie B”, and“Movie C”.

For example, the user may press a key on the remote control 91 (FIG. 10)that corresponds to the menu item to be selected from among a pluralityof menu items being displayed. Thus, one of the plurality of menu itemsis selected (step S139).

The system control section 93 receives information representing theselected menu item (e.g., the menu item number) via the remote controlreception section 92 (FIG. 12). The system control section 93 receivesthe management information packs included in the VOBs of the video menuin reproduction from the AV decoder 85. By referring to the managementinformation packs, the system control section 93 executes a controlcommand corresponding to the selected menu item (step S140).

The control command may be, for example, “TitlePlay#n”, meaning“reproduce a title having title number n”.

The system control section 93 calls a “REPRODUCTION OF TITLE INVIDEO-ORIENTED REPRODUCTION MODE” subroutine to execute the“TitlePlay#n” command (step S141).

At step S142, it is determined whether or not to return to the videomenu illustrated in FIG. 15. If the determination at step S142 is “Yes”,the process returns to step S133; if the determination at step S142 is“No”, the reproduction process is terminated.

FIG. 13B describes the flow of a reproduction process in the“REPRODUCTION OF TITLE IN VIDEO-ORIENTED REPRODUCTION MODE” subroutine.

The system control section 93 reads the title search pointer table 702(FIG. 7) from the video manager information 700 (step S151).

By referring to the title search pointer 712 (FIG. 7) corresponding totitle number n, the system control section 93 acquires the VTS number721 (FIG. 7) and the intra-VTS title number 722 (FIG. 7) (step S152).

The system control section 93 reads the video title set section titlesearch pointer table 612 (FIG. 6) from the video title set 600 (FIG. 6)corresponding to the VTS number 721 (step S153).

By referring to the start PGC number 622 (FIG. 6) corresponding to theintra-VTS title number 722, the system control section 93 calculates theaddress of the PGC information 631 (FIG. 6) to be first executed (stepS154), reads the PGC Information 631 based on that address, and retainsthe PGC information 631 within the system control section 93 (stepS157).

The system control section 93 acquires the VOB addresses 642 (FIG. 6) inaccordance with the PGC information 631 (step S156), and reproduces aVOB 602 based on that address (step S157).

At step S158, it is determined whether or not the VOB 602 is the lastVOB 602 to be reproduced. If the determination at step S158 is “Yes”,the process moves to step S159; if the determination at step S158 is“No”, the process returns to step S156.

At step S159, it is determined whether or not the PGC information 631 isthe last PGC information 631 to be reproduced. If the determination atstep S159 is “Yes”, the process moves to step S142 in FIG. 13A; if thedetermination at step S159 is “No”, the process returns to step S154.

In the case where a VOB reproduced in accordance with the PGCinformation corresponds to a menu for allowing the flow of reproductionto branch out, a menu item is displayed from the video data contained inthe reproduced VOB, as in the case of displaying a menu based on theaforementioned video manager information.

A control command which is launched via user interaction is stored in amanagement information pack of a VOB. Therefore, when receiving userinteraction through an operation of the remote control or the like, thesystem control section 93 executes the control command in the managementinformation pack of the VOB. As a result, a diversified reproductioncontrol is realized.

Although not shown in FIG. 10, the DVD player 1 is provided with aswitching key for switching between an audio channel and a sub-picturechannel. The audio channel and the sub-picture channel selected by auser using this switching key are retained in a register (not shown)within the system control section 93. When a VOB is reproduced, thesystem control section 93 refers to this register in order to designatea valid channel for the AV decoder section 85. Such a designation ismade by outputting a control signal from the system control section 93to the AV decoder section 85. As a result, only the information in thevalid audio channel and sub-picture channel is output to the exterioralong with the moving image information.

FIG. 14A shows the flow of a reproduction process in the audio-orientedreproduction mode. It is assumed herein that the reproduction mode hasalready been determined as the audlo-oriented reproduction mode.

At step S161, it is determined whether or not an optical disk is loadedin.the DVD player 1. Such determination can be performed by, forexample, the system control section 93 in accordance with a signal fromthe optical sensor.

If it is determined that an optical disk is loaded in the DVD player 1,the system control section 93 controls the rotation of the disk bycontrolling the mechanism control section 83 and the signal processingsection 84, and performs an initialization operation for causing theoptical pickup 82 to seek Into the lead-in region 31 (FIG. 3). Thus, thereproduction process is started.

At step 162, the audio manager information 900 (FIG. 3) is read from theaudio zone region 32 c (FIG. 3). This reading is performed based on theinformation which is read from the volume file management region 32 a(FIG. 3).

By referring to the audio-only title search pointer table 903 (FIG. 9)of the audio manager information 900 (step S163), the system controlsection 93 acquires the ATS numbers 954 and the intra-ATS title numbers955 in accordance with the entry order within the audio-only titlesearch pointer table 903 (step S164).

The system control section 93 calls a “REPRODUCTION OF TITLE INAUDIO-ORIENTED REPRODUCTION MODE” subroutine to reproduce a titledesignated by the ATS number 954 and the intra-ATS title number 955(step S165).

At step S166, it is determined whether or not the title is the lasttitle to be reproduced. If the determination at step S166 is “Yes”, thereproduction process is terminated; if the determination at step S166 is“No”, the process returns to step S163.

FIG. 14B describes the flow of a reproduction process in the“REPRODUCTION OF TITLE IN AUDIO-ORIENTED REPRODUCTION MODE” subroutine.

The system control section 93 reads the audio title set information 801(FIG. 8A) from the audio title set 800 corresponding to the designatedATS number 954 (step S171).

The system control section 93 reads the ATS program chain informationtable 812 from the audio title set information 801 (step S172), andreads the ATS program chain information search pointers 832 inaccordance with the entry order within the ATS program chain informationtable 812 (step S173).

By searching through the ATS_PGC category 851 of the ATS program chaininformation search pointers 832, the system control section 93determines whether or not the designated intra-ATS title number 955coincides with the intra-ATS title number 872 of the ATS_PGC category851 (step S174).

If the determination at step S174 is “Yes”, the process moves to stepS175; if the determination at step S174 is “No”, the process returns tostep S173. At step S173, another ATS program chain information searchpointer 832 is read.

The system control section 93 reads the ATS program chain informationunit 833 corresponding to the ATS program chain information searchpointer 832 in which the designated intra-ATS title number 955 is found,and retains the ATS program chain information unit 833 within the systemcontrol section 93 (step S175).

The system control section 93 acquires the ATS program information 862to be reproduced in accordance with the entry order within the ATSprogram chain information unit 833 (step S176), and determines the cellto reproduce based on the cell number described in the entry cell number833 of the ATS program information 862.

The system control section 93 acquires the ATS cell playback information863 corresponding to the ATS program information 862 (step S177). Theaddress of the cell at which the reproduction should begin is designatedby the ATS cell start address 893 of the ATS cell playback information863. The address of the cell at which the reproduction should end isdesignated by the ATS cell end address 894 of the ATS call playbackinformation 863.

Based on the ATS cell start address 893 and the ATS cell end address894, the system control section 93 calculates the address of the objectto be reproduced as well as the offset information for that object (stepS178), and reproduces the object based on this address and offsetinformation (step S179).

If the designated audio title set 800 is of an AOB point type, theobject to be reproduced is an AOB 802. The position of the AOB 802 onthe optical disk is determined based on the start address 822 e (FIG.8C) of the object region of the ATS address information 822. The AOB 802which has been reproduced from the optical disk is transferred to theaudio decoder section 94 by the system control section 93. The audiodecoder section 94 converts the AOB 802 into an audio signal, which isoutput to the exterior of the DVD player 1.

If the designated audio title set 800 is of a VOB point type, the objectto be reproduced is an VOB 602. The position of the VOB 602 on theoptical disk is determined based on the start address 822 e (FIG. 8C) ofthe object region of the ATS address information 822. The VOB 602 whichhas been reproduced from the optical disk is processed so that thebeginning data and the ending data of the VOB 602 are trimmed based onthe offset information. The data of the thus-processed VOB 602 istransferred to the AV decoder section 85.

Prior to the transfer of the data of the VOB 602, the system controlsection 93 outputs a decode medium restriction instruction to the AVdecoder section 85. Following the decode medium restriction instruction,the AV decoder section 85 decodes only the data of the audio packsincluded in the VOB 602, thereby converting the data of the VOB 602 intoan audio signal. The audio signal is output to the exterior of the DVDplayer 1.

Next, the operation of the DVD player 1 in the video-orientedreproduction mode and the operation of the DVD player 1 in theaudio-oriented reproduction mode will be more specifically describedwith reference to FIGS. 16A and 16B.

FIG. 16A illustrates the content of exemplary data of animage-accompanied music application. This application includes a liverecording of a concert by a certain singer.

VOB#1 to VOB#6 are stored as moving image information 160 on the opticaldisk. AOB#1 to AOB#4 are stored as audio information 162 on the sameoptical disk on which VOB#1 to V0#6 are stored.

VOB#2 includes the moving image information of “Song A”. Herein, it isassumed that “Song A” shows the image of the audience entering theconcert hall for a period of time, “t1”, at the beginning, followed bythe actual performance and singing of Song A for a period of time, “t2”.VOB#3 includes the moving image information of an “Interview with thesinger”. VOB#4 includes the moving image information of “Song B”. VOB#5includes the moving image information of “Song C”. VOB#6 includes themoving image information of “Song D” ending the concert. It is assumedthat “Song D” shows the actual performance and singing of Song D for aperiod of time, “t3”, followed by the image of the audience leaving theconcert hall for a period of time, “t4”.

VOB#1 includes the moving image information of a video menu to bedisplayed at the beginning of reproduction. The video menu is used fordetermining which one of “Song A”, “Song B”, “Song C”, “Song D”, or“Interview with the singer” to reproduce, and accordingly diversify thereproduction path of the VOBs.

Each of VOB#1 to VOB#6 includes audio information in the LPCM format (16bit-sampled) and sub-picture information for displaying subtitles of thewords of the songs.

Each of AOB#1 to AOB#4 includes audio information in the LPCM format (24bit-sampled). Thus, each of AOB#1 to AOB#4 includes audio information ofa higher sound quality than that of VOB#1 to VOB#6.

AOB#1 includes the audio information of “Song B′”. The content of theaudio information of “Song B′” is the same as that of the audioinformation of “Song B” except that the audio information of “Song B′”is of a higher quality than that of the audio information of “Song B”.

AOB#2 includes the audio information of “Song C′”. The content of theaudio information of “Song C′” is the same as that of the audioinformation of “Song C” except that the audio information of “Song C′”is of a higher quality than that of the audio information of “Song C”.

AOB#3 includes the audio information of “Song#E”. AOB#4 includes theaudio information of “Song#F”.

FIG. 16B shows reproduction paths for reproducing the image-accompaniedmusic application shown in FIG. 16A.

In FIG. 16B, reference numeral 164 shows a reproduction path in thevideo-oriented reproduction modes, whereas reference numeral 166 shows areproduction path in the audio-oriented reproduction mode. Therespective objects stored on the optical disk are reproduced along aspecified reproduction path.

In the video-oriented reproduction mode, the start menu corresponding toVOB#1 is displayed before beginning the reproduction, and a user Inputis awaited. A user selects one of a plurality of menu Items in the startmenu, such selection being made by an operation of a remote control, forexample. The plurality of menu items are respectively associated withVOB#2 to VOB#6 in advance. A VOB corresponding to the menu item selectedby the user is reproduced, so that a video signal and an audio signalcorresponding to the reproduced VOB are output.

The reproduction path 164 is defined so as to branch into one of VOB#2to VOB#6 after the reproduction of VOB#1. The reproduction path 164 isdefined by the PGC information 631 (FIG. 6).

In the case where reproduction is performed along the reproduction path164, “Song A” corresponding to VOB#2 is reproduced for a period of time,“T1”, without an offset, and “Song D” corresponding to V0B#6 isreproduced for a period of time, “T2”, without an offset.

In the audio-oriented reproduction mode, VOB#2, AOB#1, AOB#2, VOB#6,AOB#3, and AOB#4 are reproduced in this order. However, as for VOB#2 andVOB#6, only the audio information thereof is reproduced, withoutreproducing the video information thereof. As a result, an audio signalcorresponding to the reproduced VOB or the reproduced AOB is output.

The reproduction path 166 is defined so that VOB#2, AOB#1, AOB#2, VOB#6,AOB#3, and AOB#4 are reproduced in this order. The reproduction path 166is defined by the ATS program chain information 832 (FIGS. 8A and 8B).

In the case where reproduction is performed along the reproduction path166, “Song A” corresponding to VOB#2 is reproduced first. However, thefirst “T1” period of time of “Song A”, which is not suitable for audiooutput, is cut off so that “Song A” will be reproduced for the “t2”period of time, not the full “T1” period of time. Such omission In theplayback time is performed based on offset information (i.e., ATS cellplayback information 863 (FIGS. 8A and 8B). After the reproduction ofVOB#2 is complete, “Song B′” corresponding to AOB#1 is reproduced at ahigher quality than that of “Song B”. After the reproduction of AOB#1 iscomplete, “Song C′” corresponding to AOB#2 is reproduced at a higherquality than that of “Song C”. After the reproduction of AOB#2 iscomplete, “Song D” corresponding to VOB#6 is reproduced. However, thelast “t4” period of time of “Song D”, which is not suitable for audiooutput, is cut off so that “Song D” will be reproduced for the “t3”period of time, not the full “T2” period of time. Such omission in theplayback time is performed based on offset information (i.e., ATS cellplayback information 863 (FIGS. 8A and 8B). After the reproduction ofVOB#6 is complete, “Song E” corresponding to AOB#3 is reproduced. Afterthe reproduction of AOB#3 is complete, “Song F” corresponding to AOB#4is reproduced.

FIG. 17 shows an example of specific data arrangement on the opticaldisk. In this example, it is assumed that the addresses of the opticaldisk are arranged in an ascending order from top to bottom.

In the example shown in FIG. 17, an audio zone region 32 c is assignedwith a smaller address than that of a video zone region 32 b.Alternatively, the audio zone region 32 a may be assigned with a largeraddress than that of a video zone region 32 b.

The audio zone region 32 c includes an audio manager (AMG) and two audiotitle sets (ATS#1, ATS#2) arranged therein. The audio manager (AMG)includes audio manager information (AMGI) and an audio manager menu(AMG_Menu).

Since the audio title set (ATS#1) is an ATS of the VOB point type, theaudio title set (ATS#1) only includes audio title set information(ATSI#1). Since the audio title set (ATS#2) is an ATS of the AOB pointtype, the audio title set (ATS#2) includes audio title set information(ATSI#2) and audio objects (ATS#2 AOBs).

The video zone region 32 b includes a video manager (VMG) and a videotitle set (VTS#1) arranged therein. The video manager (VMG) includesvideo manager information (VMGI) and an video manager menu (VMG_Menu).The video title set (VTS#1) includes video title set information(VTSI#1) and video objects (VTS#1 VOBs).

The audio manager information (AMGI) includes audio-only title searchpointer table information (AOTT_SRPTI) that is referred to by anaudio-only player, and audio title search pointer table information(ATT_SRPTI) that is referred to by an audio player with video functions.The audio-only title search pointer table information (AOTT_SRPTI) onlypoints to audio titles included in ATS#1 and ATS#2, whereas the audiotitle search pointer table information (ATT_SRPTI) points to not onlysuch audio titles but also a title of the video manager (VMG) in orderto achieve image-accompanied reproduction (see arrow 171).

The audio title set information (ATSI#1) includes ATS program chaininformation (ATS_PGCI#1, ATS_PGCI#2) for defining the reproduction orderof objects. Since ATS#1 does not include AOBs, the ATS program chaininformation (ATS_PGCI#1, ATS_PGCI#2) points to the VOBs included inVTS#1. Specifically, ATS_PGCI#1 points to VOB#2 (see arrow 172), whereasATS_PGCI#2 points to VOB#6 (see arrow 173).

The audio title set information (ATSI#2) includes ATS program chaininformation (ATS_PGCI#1, ATS_PGCI#2) for defining the. reproductionorder of objects. Since ATS#2 includes AOBs, the ATS program chaininformation (ATS_PGCI#1, ATS_PGCI#2) points to the AOBs in ATS#2.Specifically, ATS_PGCI#1 points to AOB#1 (see arrow 174), whereasATS_PGCI#2 points to AOB#2 (see arrow 175).

The video title set information (VTSI#1) includes PGC information(PGCI#1 to PGCI#3) for defining the reproduction order of objects. ThePGC information (PGCI#1 to PGCI#3) all point to the VOBs in VTS#1.

FIG. 18 shows a reproduction order of objects in the video-orientedreproduction mode and a reproduction order of objects in theaudio-oriented reproduction mode.

In the video-oriented reproduction mode, a video object (VOB#1) of thevideo manager (VMG) is reproduced first so that a start menucorresponding to VOB#1 is displayed. A desired title is selected inaccordance with a user input. Once the selection of a desired title ismade, the PGC information (PGC#1, PGC#2, and PGC#3) of the video titleset (VTS#1) is reproduced in accordance with the title search pointertable (TT_SRPT) serving as navigation information for the video manager(VMG). In accordance with this navigation information, “Song A”,“Interview with the singer”, “Song B”, “Song C”, and “Song D” arereproduced.

In the audio-oriented reproduction mode, ATT#1, ATT#3, ATT#4, and ATT#5are reproduced in this order, in accordance with the audio-only titlesearch pointer table (AOTT_SRPT) serving as navigation information forthe audio manager (AMG). ATT#1 points to cell#2 of VOB#2 of VTS#1 (viaPGC#1 of ATS#1). ATT#3 points to AOB#1 (via PGC#1 of ATS#2). ATT#4points to AOB#2 (via PGC#2 of ATS#2). ATT#5 points to cell#1 of VOB#6 ofVTS#1 (via PGC#2 of ATS#1). Thus, the audio-only player will reproducethe latter half of “Song A”, “Song B′” (high quality), “Song C′” (highquality), and the first half “Song D”. The “Interview with the singer”,the first half of “Song A”, and the latter half of “Song D” are notreproduced.

As described above, It is possible to selectively reproduce only thedata which is appropriate for audio reproduction according to thepresent example of the invention. Specifically, in an audio-orientedreproduction mode, it is possible to cut off any audio data which theauthor of the title considers as meaningless without being reproducedalong with images, e.g., selection menus which would be reproduced in avideo-oriented reproduction mode that require user interaction, thenoise of a leaving audience, and the like. Thus, the author of a giventitle can provide an optical disk which allows the reproduction of atitle in accordance with a selected one of the optimum reproductionorder for the video-oriented reproduction mode and the optimumreproduction order for the audio-oriented reproduction mode.

Furthermore according to the present example, a user can enjoy higherquality sounds and voices in the audio-oriented reproduction mode thanin the video-oriented reproduction mode.

In the present example, it is assumed that it is determined at thebeginning of reproduction whether the reproduction mode is avideo-oriented reproduction mode or an audio-oriented reproduction mode.However, the reproduction mode may be changed during reproduction. Ifthe reproduction mode to changed to the video-oriented reproduction modeduring reproduction under the audio-oriented reproduction mode, thereproduction order which was initially established in the audio-orientedreproduction mode may be maintained after the change of reproductionmode, so that images and sounds/voices are output in the case where thereproduced object is a VOB. In this case, the present embodiment can bearranged so as to prohibit the system control section 93 from outputtinga decode medium restriction instruction to the AV decoder section 85during reproduction of a VOB.

EXAMPLE 2

Hereinafter, the reproduction by an audio player with video functionswill be described. The structure of an audio player with video functionsis the same as that of the DVD player 1 shown in FIG. 12 except that theaudio player with video functions is arranged so that the determinationas to whether the reproduction mode is going to be a video-orientedreproduction mode or an audio-oriented reproduction mode is notperformed before a reproduction process. The audio player with videofunctions is defined as an audio player which is specially designed foraudio purposes but additionally has an image displaying function.

FIG. 19 shows the flow of a reproduction process by the audio playerwith video functions.

At step S191, it is determined whether or not an optical disk is loadedin the audio player with video functions. Such determination can beperformed in accordance with, for example, a signal from an opticalsensor.

If it is determined that an optical disk is loaded in audio player withvideo functions, the rotation of the disk is controlled so that aninitialization operation for causing the optical pickup to seek into thelead-in region 31 (FIG. 3) is performed. Thus, the P16584 reproductionprocess is started.

At step S192, the audio manager information 900 (FIG. 3) is read fromthe audio zone region 32 c (FIG. 3). This reading is performed based onthe information which is read from the volume file managementinformation 32 a (FIG. 3).

At step S193 the audio title search pointer table 902 (FIG. 9) of theaudio manager information 900 is referred to.

At step S194, the AOTT/AVTT flag 961 of the audio title category 931 isread.

At step S195, the value of the AOTT/AVTT flag 961 is checked. If thevalue of the AOTT/AVTT flag 961 is a value representing AOTT, theprocess moves to step S196. If the value of the AOTT/AVTT flag 961 is avalue representing AVTT, the process moves to step S198.

At step S196, an ATS number 934 and an intra-ATS title. number 935 inthe audio title search pointer table 902 are acquired.

At step S197, the “REPRODUCTION OF TITLE IN AUDIO-ORIENTED REPRODUCTIONMODE” subroutine (FIG. 14B) is called. The details of the reproductionprocess have already been described with reference to FIG. 14B.

At step S198, the “REPRODUCTION OF TITLE IN VIDEO-ORIENTED REPRODUCTIONMODE” subroutine (FIG. 14B) is called. The details of the reproductionprocess have already been described with reference to FIG. 13B.

Thus, in the reproduction by the audio player with video functions, thereproduction of a title in the audio-oriented reproduction mode and thereproduction of a title in the video-oriented reproduction mode areautomatically switched depending on the value of the AOTT/AVTT flag 961.

At step S199, it is determined whether or not the title is the lasttitle to be reproduced. If the determination at step S199 is “Yes”, thereproduction process is terminated; if the determination at step S199 is“No”, the process returns to step S193.

Nest, a specific example of reproduction by the audio player with videofunctions will be described with reference to FIG. 18.

ATT#1, ATT#2, ATT#3, ATT#4, and ATT#5 are reproduced in this order, inaccordance with the audio title search pointer table (ATT_SRPT) servingas navigation information for the audio manager (AMG). ATT#1, ATT#3,ATT#4, and ATT#5 are reproduced In the same manner as in the case ofbeing reproduced in accordance with the audio-only title search pointertable (AOTT_SRPT). ATT#2 includes a description for causing title#2 ofthe video manager (VMG) to be reproduced. As a result, the audio playerwith video functions reproduces only the sounds and voices of the latterhalf of “Song A”, “Song B′” (high quality), “Song C′” (high quality),and the first half “Song D” as in the case of an audio-only player,whereas the audio player with video functions reproduces the start menu(VOB#1′) of the audio manager (AMG) and the “Interview with the singer”along with the images.

The difference between the audio title search pointer table (ATT_SRPT)and the audio only title search pointer table (AOTT_SRPT) is that onlyATT_SRPT is capable of pointing to a title in the video zone region. Inthe example shown in FIG. 18, ATT#2 points to a title in the video zoneregion. The concept of title groups is Introduced because of suchdifferences. Titles within a title group must always be consecutivelyreproduced.

In the example shown in FIG. 18, AOTT_SRPT includes the title groupsAOTT_GR#1 and AOTT_GR#2. ATT#1 belongs to AOTT_GR#1. ATT#3, ATT#4, andATT#5 belong to AOTT_GR#2. The title groups ATT_GR#1, ATT_GR#2, andATT_GR#3 are included in ATT_SRPT. ATT#1 belongs to ATT_GR#1. ATT#2belongs to ATT_GR#2. ATT#3, ATT#4, and ATT#5 belong to ATT_GR#3. Owingto this construction, consistency with respect to the reproduction orderand the title numbers Is maximized between the audio player with videofunctions and the audio-only player, thereby preventing the user frombeing confused as to the reproduction order and the titles.

FIG. 20A shows a specific example of title search pointer tableinformation.

The management information concerning the five titles ATT#1 to ATT#5 isdescribed in the audio title search pointer table information(ATT_SRPTI) and the audio-only title search pointer table information(AOTT_SRPTI).

ATT#2 in ATT_SRPTI points to a title (TT#2 of VTS#1) of the videomanager (VMG). Therefore, TT#2 of VTS#1 is to be reproduced during thereproduction by the audio player with video functions.

On the other hand, the column of the management informationcorresponding to ATT#2 in AOTT_SRPTI is blank. Therefore, TT#2 of VTS#1is not reproduced during the reproduction by the audio-only player.

FIG. 20B shows a specific example of the ATS program chain informationtable (ATS_PGCIT.) of an ATS (ATS#2) of the AOB point type. In thisexample, the ATS program chain information table (ATS_PGCIT) includestwo ATS program chain Information units (ATS_PGCI#1, ATS_PGCI#2). TheATS program chain information (ATS_PGCI#1) includes one program and onecell, designating cell#1 of AOB#1. The ATS program chain information(ATS_PGCI#2) includes one program and one cell, designating cell#1 ofAOB#2.

FIG. 20C shows a specific example of the ATS program chain informationtable (ATS_PGCIT) of an ATS (ATS#2) of the VOB point type. In thisexample, the ATS program chain information table (ATS_PGCIT) includestwo ATS program chain information units (ATS_PGCI#1, ATS_PGCI#2). TheATS program chain information (ATS_PGCI#1) includes one program and onecell, designating cell#2 of VOB#2 of VTS#1. The ATS program chaininformation (ATS_PGCI#2) includes one program and one cell, designatingcell#1 of VOB#6 of VTS#1.

EXAMPLE 3

Hereinafter, an optical disk that allows switching of the audioinformation to be reproduced depending on the audio reproducingcapabilities of the reproduction apparatus, as well as an apparatus anda method for reproducing the same, will be described.

The structure of the reproduction apparatus of the present example isthe same as that of the DVD player 1 shown in FIG. 12 except that thereproduction apparatus of the present example is arranged so that thedetermination as to whether the reproduction mode is going to be avideo-oriented reproduction mode or an audio-oriented reproduction modeis not performed before a reproduction process. The reproductionapparatus of the present example is defined as an audio player which isspecially designed for audio purposes.

The data structure stored on the optical disk is the same as the datastructure stored on the optical disk according to Example 1.

FIG. 21A shows exemplary data to be stored on the optical disk.

AOB#1 is obtained by expressing “Song A” in accordance with thefollowing audio attributes: LPCM; sampling frequency (48 kHz);quantization bit number (16 bits); channel number (2).

AOB#2 is obtained by expressing “Song B” in accordance with thefollowing audio attributes: LPCM; sampling frequency (96 kHz);quantization bit number (24 bits); channel number (2). AOB#3 is the samecontent as that of AOB#2 but expressed in different audio attributestherefrom. Specifically, AOB#3 is obtained by expressing “Song B” inaccordance with the following audio attributes: LPCM; sampling frequency(48 kHz); quantization bit number (16 bits); channel number (2).

AOB#4 is obtained by expressing “Song C” in accordance with thefollowing audio attributes: LPCM; sampling frequency (96 kHz);quantization bit number (24 bits); channel number (6). AOB#5 is the samecontent as that of AOB#4 but expressed in different audio attributestherefrom. Specifically, AOB#5 is obtained by expressing “Song C” inaccordance with the following audio attributes: LPCM; sampling frequency(96 kHz); quantization bit number (24 bits); channel number (2).

AOB#6 is obtained by expressing “Song D” in accordance with thefollowing audio attributes: LPCM; sampling frequency (96 kHz);quantization bit number (24 bits); channel number (2). AOB#7 is the samecontent as that of AOB#6 but expressed in different audio attributestherefrom. Specifically, AOB#7 is obtained by expressing “Song D” inaccordance with the following audio attributes: LPCM; sampling frequency(48 kHz); quantization bit number (16 bits); channel number (6).

VOB#1 represents “Song E”. VOB#1 includes two audio streams (Stream#1,Stream#2). The audio stream (Stream#1) is expressed in accordance withthe following audio attributes: DTS; channel number (6). The audiostream (Stream#2) is expressed in accordance with the following audioattributes: LPCM; sampling frequency (96 kHz); quantization bit number(24 bits); channel number (2).

AOB#8 is obtained by expressing “Song F” in accordance with thefollowing audio attributes: LPCM; sampling frequency (48 kHz);quantization bit number (16 bits); channel number (2).

Such data Structure allows each reproduction apparatus to reproducevoices and sounds of the highest quality and performance possible withits own audio reproduction capabilities. For example, differentsounds/voices will be reproduced when an optical disk having the datastructure shown in FIG. 21A is loaded in a reproduction apparatus withaudio reproduction capabilities such as LPCM; sampling frequency (96kHz); channel number (6), as compared to what is reproduced when theoptical disk having the data structure shown in FIG. 21A is loaded in areproduction apparatus with audio reproduction capabilities such asLPCM; sampling frequency (48 kHz); DTS.

FIG. 21B shows the reproduction order of the data of FIG. 21B by using areproduction apparatus with the following reproduction capabilities:LPCM; sampling frequency (96 kHz); channel number (6). In this case,AOB#1, AOB#2, AOB#4 are reproduced in this order, as shown in FIG. 21B,followed by either AOB#6 or AOB#7. It is previously determined as towhether AOB#6 or AOB#7 will be reproduced, depending on the preferencebetween quality and multichannel capabilities. Such a decision is madein accordance with a user input or the attributes of the reproductionapparatus itself. Thereafter, Stream#2 of VOB#1 and AOB#8 arereproduced. Thus, reproduction is performed with the highest quality andperformance that is available given the audio reproduction capabilitiesof the reproduction apparatus.

FIG. 21C shows the reproduction order of the data of FIG. 21B by using areproduction apparatus with the following reproduction capabilities:LPCM; sampling frequency (48 kHz); DTS. In this case, AOB#1 and AOB#3are reproduced in this order, as shown in FIG. 21C. Since samplingfrequencies for AOB#4 and AOB#5 are both 96 kHz, AOB#5 is reproduced bydown-converting the sampling frequencies into 48 kHz. Thereafter, AOB#7,Stream#1 of VOB#1, and AOB#8 are reproduced. Thus, reproduction isperformed with the highest quality and performance that is availablegiven the audio reproduction capabilities of the reproduction apparatus.

The PGC block data structure is adopted in order to realize suchselective reproduction.

FIG. 22 shows the data structure of a PGC block. In the example shown inFIG. 22, PGC#1 and PGC#2 of ATS#1; PGC#2 and PGC#3 of ATS#2; PGC#4 andPGC#5 of ATS#2; and PGC#6 and PGC#7 of ATS#2 each constitute a PGCblock. The audio title search pointer table (AOTT_SRPT) indicating thereproduction order describes ATT#1 to ATT#6. Two PGCs in the PGC blockare pointed to from the same title.

FIGS. 23A to 23E show a specific example of title search pointer/PGCstructure.

FIG. 23A shows a specific example of the title search pointer table(ATT_SRPT). An ATS number, an intra-ATS title number, and an intra-ATTprogram number are described for each of ATT#1 to ATT#6. From thesedescriptions, the PGC which an ATT points to can be known. Thus, theobject to be reproduced is specified.

FIG. 23D shows a specific example of an ATS (ATS#2) of the AOB pointtype. An intra-ATS title number, a block mode, a block type, an audiocoding mode, and a channel number are described for each of PGC#1 toPGC#8. The intra-ATS title number is designated by a title searchpointer. The block mode indicates which portion of the PGC block the PGCis in. In the block mode, “0” is stored if it is not a PGC block; “1” isstored if the PGC is the first PGC of the block; “3” is stored if thePGC is the last PGC of the block. The block type indicates the degree ofdifferences between the PGCs constituting a PGC block. In the blocktype, “0” is stored if it is not a PGC block; “1” is stored if the audiocoding mode is different; “2” is stored if the channel number isdifferent; “3” is stored if both the audio coding mode and the channelnumber are different. By referring to the block type, the reproductionapparatus can easily know which stream is appropriate for its ownreproduction capabilities. It will be appreciated that the programinformation is omitted from this example.

In the example shown in FIG. 23B, PGC#2 and PGC#3 are blocks havingdifferent audio coding modes; specifically, PGC#2 has a samplingfrequency of 96 kHz, whereas PGC#3 has a sampling frequency of 48 kHz.PGC#4 and PGC#5 are blocks having different channel numbers;specifically, PGC#4 has six channels, whereas PGC#5 has two channels.PGC#6 and PGC#7 are blocks having different audio coding modes anddifferent channel numbers; specifically, PGC#6 has a sampling frequencyof 96 kHz and two channels, whereas PGC#7 has a sampling frequency of 48kHz and six channels.

FIG. 23C shows a specific example of an ATS (ATS#1) of the VOB pointtype. In this example, PGC#1 and PGC#2 have different audio coding modesand different channel numbers; specifically, PGC#1 has a DTS audiocoding mode and six channels, whereas PGC#2 has a LPCM audio coding modeand two channels.

FIG. 23D shows the audio attributes of the ATS management table ofATS#2. FIG. 23E shows the audio attributes of the ATS management tableof ATS#1.

FIGS. 24A and 24B show the flow of a reproduction process in which theaudio information to be reproduced is switched depending on the audioreproducing capabilities of the reproduction apparatus.

The flow up to the acquisition of the ATS number and the intra-ATS titlenumber is the same as in the reproduction process in the audio-orientedreproduction mode shown in FIG. 14A, and the description thereof isomitted. At step S165 in FIG. 14A, the “REPRODUCTION OF TITLE INAUDIO-ORIENTED REPRODUCTION MODE” subroutine in FIG. 24A is calledinstead of the “REPRODUCTION OF TITLE IN AUDIO-ORIENTED REPRODUCTIONMODE” subroutine in FIG. 14B.

At step S241, the audio title set information 801 (FIG. 8A) is read fromthe audio title set 800 corresponding to the designated ATS number 954.Furthermore, various attribute information Is read (steps S242, S243).

At step S244, by searching through the ATS_PGC category 851 of the ATSprogram chain information search pointers 832, the ATS_PGC category 851that include an intra-ATS title number 872 coinciding with thedesignated intra-ATS title number 955 are located.

If the block type 874 of the located ATS_PGC category 851 is not 0,(step S245), the ATS program chain information 833 has a PGC blockstructure. One of the two ATS program chain information units 833 in theFGC block that is to be reproduced is selected (step S246). Suchselection is executed by a “SELECTION OF PGC IN THE BLOCK” subroutine(FIG. 24B).

Thereafter, the selected ATS program chain information 833 is read so asto be retained within the reproduction apparatus (step S247). The ATSprogram information 862 to be reproduced is acquired in accordance withthe entry order within the ATS program chain information unit 833 (stepS248).

A program is reproduced in accordance with the ATS program information862. In the reproduction of the program, the ATS cell playbackinformation 863 is sequentially acquired (step S249); the address of anobject (AOB or VOB) which is pointed to by the cell is calculated (stepS250); and the object is reproduced based on that address (step S251).Steps S249 to S251 are repeated until reaching the last cell to bereproduced. The title reproduction is terminated as the reproduction ofthe last program is completed.

FIG. 24B shows the flow of a reproduction process in the “SELECTION OFPGC IN THE BLOCK” subroutine.

If there is no reproduction designation of blocks or the blockreproduction designation is directed to the first PGC (step 8261), it isdetermined whether or not the first PGC.is reproducible (step S262).

If the block type is 1 (step S264), the audio coding mode is read (stepS265), and it is determined whether or not the sounds/voices arereproducible (step S266). If the sounds/voices are reproducible, theselection of PGCs is ended after steps S267 and S268. If thesounds/voices are not reproducible, the next PGC is selected (stepS253).

If the block type is 2 (step S269), the channel number is read (stepS270), and it is determined whether or not the sounds/voices arereproducible (step S271). If the sounds/voices are reproducible, theselection of PGCs is ended after steps S267 and S268. If thesounds/voices are not reproducible, the next PGC is selected (stepS263).

If the block type is 3 (step S272), the audio coding mode and thechannel number are read (step S273), and it is determined whether or notthe sounds/voices are reproducible (step S274). If the sounds/voices arereproducible, the selection of PGCs is ended after steps S275 and S276.If the sounds/voices are not reproducible, the next PGC is selected.

If the block type is neither 1, 2, nor 3, error processing is performed(step S279). If the current PGC is not reproducible and the current PGCIs already the last PGC., error processing is performed because noreproducible PGCs were found (step S278).

It is possible to select which one of a plurality of PGCs included in aPGC block to reproduce in accordance with a user operation or command.It will be appreciated that, in order for a PGC to be reproduced, thereproduction apparatus must be capable of reproducing that PGC. Thisfunction will be effective in the case of an external decoder, D/Aconverter, eta., where the reproduction apparatus itself does not knowits reproduction capabilities.

In the case where the reproduction apparatus is capable of reproducingany one of a plurality of PGCs included in the PGC block, the followingmethods are available: a method in which the first PGC (PGC#1) isreproduced and a method in which a flag (precedence reproduction controlinformation) indicating which one of a plurality of PGCs must takeprecedence in reproduction.

EXAMPLE 4

In the case where one disk includes video-oriented contents andaudio-oriented contents, or where the same disk may be reproduced byplayers having different reproduction methods, the author of the titlewishes to predict a certain reproduction environment. Such reproductionenvironment includes users' modes of viewing/listening, e.g., that theydefinitely want to reproduce images or that they want to give precedenceto sounds/voices over images, for example. Examples of players havingdifferent reproduction methods include video players for video-orientedreproduction, audio-only players for audio-oriented reproduction, oraudio players with video functions for audio-oriented reproduction whichare also capable of reproducing images.

With respect to reproduction of a title, it is very desirable for anauthor of any title to be able to define a reproduction situation, inaccordance with such types of players and environmental conditions, sothat the intent of author is properly understood by theviewers/listeners. This would promote the creation of even higherquality titles. In the present example, the data structure and theoperation of a player which makes possible the creation of such titles.The fundamental data structure, player structure, and player operationare the same as those described in Example 1.

1. A case where reproduction by an audio-only player is not performed(see FIG. 25):

In the case where it is desirable that the images are always reproduced,reproduction by an audio-only player can be prohibited. In order torealize this, for example, a disk structure may be adopted whichincludes no ATS's but includes only ATS's indicating VTS titles in theATT_SRPT of the AMG, as shown in FIG. 25. This disk structure allows anaudio-only player to reproduce nothing, while allowing an audio playerwith video functions to reproduce sounds/voices along with images, asdoes a video player (except for navigation commands and the like). Thesounds/voices which are available in this case are within the limits ofwhat is defined for video players and is mandatory for audio players.

2. A case where an audio player with video functions is intended toperform the same reproduction as the reproduction by a video player(reproduction with precedence to images) (see FIG. 26):

An audio-only player may be allowed to reproduce sounds/voices only,while allowing an audio player with video functions to reproduce imageswith precedence over sounds/voices. In order to realize this, forexample, a disk structure may be adopted which only includes VOB pointtype ATS's and further includes ATTs in the ATT_SRPT and AOTT_SRPT ofthe AMG such that PGCs of VOB point type ATS's point to VOBs in thevideo zone region, and includes an ATS representing a title of a VTS atthe beginning of the ATT_SRPT, as shown in FIG. 26. This disk structureallows an audio-only player to reproduce only the sounds/voices of theVOBs in the video zone region in accordance with the AOTT_SRPT, whileallowing an audio player with video functions to reproduce thesounds/voices of the VOBs in the video zone region along with images.The sounds/voices which are available in this case are within the limitsof what is defined for video players and is mandatory for audio players.

3. A case where an audio player with video functions is intended toreproduce sounds/voices of the same quality as, or higher quality than,that provided by a video player (see FIGS. 27 and 28):

An audio-only player is capable of reproducing sounds/voices of higherquality than that provided by a video player. An audio player with videofunctions may be allowed to selectively reproduce sounds/voices of thesame quality as, or higher quality than, that provided by a videoplayer. In order to realize this, for example, a disk structure may beadopted which includes AOB point type ATS's and includes ATTs in theATT_SRPT and AOTT_SRPT of the AMG such that PGCs of ATS's point to AOBs,and Includes an ATS representing a title of a VTS in the ATT_SRPT, asshown in FIGS. 27 and 28. This disk structure allows an audio-onlyplayer to reproduce sounds/voices of higher quality than that definedfor a video player, while allowing an audio player with video functionsto reproduce sounds/voices of higher quality than, or the same qualityas, that provided by a video player.

The difference between the reproduction method illustrated in FIG. 27and the reproduction method illustrated in FIG. 28 is whether an audioplayer with video functions gives precedence to the reproduction ofimage-accompanied sound/voices or the reproduction of high qualitysound/voices. In the example of FIG. 27, image-accompanied sound/voicesare associated with a title group bearing a smaller number than thatwhich high quality sounds/voices are associated with. In the example ofFIG. 28, high quality sounds/voices are associated with a title groupbearing a smaller number than that which image-accompanied sound/voicesare associated with. In the operation with a remote control or the like,title groups are usually reproduced in the order of title group numbers,so that title groups bearing smaller numbers are likely to be reproducedfirst. It will be appreciated, too, that it is possible to reproduceeither image-accompanied sound/voices or high quality sounds/voices byway of a menu.

4. A case where an audio player with video functions is intended toreproduce high quality sounds/voices (see FIG. 29):

Both an audio-only player and an audio player with video functions maybe allowed to reproduce high quality sound/voices. In order to realizethis, a disk structure may be adopted which includes AOB point typeATS's and includes ATTS in the ATT_SRPT and AOTT_SRPT of the AMGsuch.that PGCs of ATS's point to AOBs, and that the VOBs in the videozone region are never pointed to from the audio zone region, as shown inFIG. 29. This disk structure allows both an audio-only player and anaudio player with video functions to reproduce high qualitysounds/voices, while allowing a video player to reproduceimage-accompanied sounds/voices.

5. A case where a video player is prohibited from reproduction (see FIG.30):

A video player may be prohibited from reproduction. In order to realizethis, a disk structure may be adopted which does not include a videozone region, as shown in FIG. 30. This disk structure prohibits a videoplayer from reproducing a disk because of lack of a video zone region,but allows both an audio player with video functions and an audio-onlyplayer to reproduce high quality sounds/voices alike.

Thus, by selecting an appropriate data structure, the author of a titlecan designate the reproduction method by a video player, an audio playerwith video functions, and an audio-only player. In addition, it becomespossible to change the reproduction method of the player at thebeginning or in the middle of the reproduction of a disk, by anarrangement such that the player can be determined either to behave as avideo player or as an audio player with video functions or as anaudio-only player depending on whether or not a display is connected tothe player or on whether or not the reproduction of images is allowed.

EXAMPLE 5

In the case of a video disk, First_Play_PGC is defined as a region fordescribing a command which is automatically executed when the disk isinserted because this Is necessitated by the use of a menu and the needto realize various settings of the player through commands. However,since an audio player does not necessarily require a menu and videoattributes can be dispensed with, there is no need to fix settingsthrough commands prior to beginning reproduction. However again, if theaudio player did not start reproduction until a “play” key is pressedafter insertion of a disk, as in the case of a CD, it would beinconvenient because the user is required to perform so much moreaction. Hereinafter, a disk data structure and a reproduction method fora player will be described which contemplates automatic execution whileconforming to the aforementioned nature of audio players.

Since the fundamental data structure and player structure are the sameas those described in Example 1, the following description will bedirected to the differences.

FIG. 31 shows the data structure of audio manager information (AMGI).The audio manager management table (AMGI_MAT), although not described indetail in Example 1, includes an autoplay flag (AP_INF). The value “1”of the autoplay flag means that the reproduction will be started atATT#1 of title group#1.

Once a disk is inserted, an audio player reads the audio manager andBets various attributes. After completion of the initial settings, theaudio player reads the autoplay flag. If the value of the autoplay flagis 1, the reproduction will be started at ATT#1 of title group#1. Thatis, the disk will immediately start reproducing sounds/voices uponinsertion without requiring the user to perform more operation.

Thus, the need for pressing a “Play” key after insertion of a disk canbe eliminated while realizing a reproduction as intended by the author.

According to the present invention, there is provided an optical disk onwhich first path information and second path information are stored, thefirst path information indicating a first reproduction path includingonly video objects, and the second path information indicating a secondreproduction path including a combination of video objects and audioobjects.

In a video-oriented reproduction mode, the video information and theaudio information contained in the video objects are reproduced alongthe first reproduction path. In an audio-oriented reproduction mode, theaudio information contained in the video objects and the audioinformation contained in the audio objects are reproduced along thesecond reproduction path. Thus, the reproduction path can be switched inaccordance with the reproduction mode. Thus, the second reproductionpath can be formed so as to exclude those video objects which areinappropriate for the exclusive reproduction of audio information.Moreover, malfunctioning in the audio-oriented reproduction mode can beprevented.

According to the present invention, the second path information includesoffset information for designating a range to be reproduced of the audioinformation contained in the video objects. As a result, those periodswhich are inappropriate for the exclusive reproduction of audioinformation can be eliminated during a period for reproducing the audioinformation in one video object.

According to the present invention, the quality of the audio informationcontained in the audio objects is higher than the quality of the audioinformation contained in the video objects. As a result, sounds andvoices of higher quality than that available during reproduction in avideo-reproduction mode can be enjoyed during reproduction in anaudio-oriented reproduction mode.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

What is claimed is:
 1. An optical disk comprising: a video zone regionfor storing at least one video object and a video title set informationfor managing the reproduction of at least one video object; and an audiozone region for storing at least one audio object and an audio title setinformation for managing the reproduction of at least one audio object,wherein each of the at least one video object contains video informationin the form of a coded video stream and first audio information in theform of at least one coded audio stream, the video title set informationcontains a first reproduction path information indicating the order ofreproducing the at least one video object so that the video informationand the first audio information contained in the at least one videoobject are reproduced in a video-oriented reproduction mode, each of theat least one audio object contains second audio information in the formof at least one coded audio stream, at least one coding type of the atleast one coded audio stream of the second audio information having ahigher sound quality than all coding types of the at least one codedaudio stream of the first audio information, the audio title setinformation contains a second reproduction path information indicatingthe order of reproducing the at least one video object and the at leastone audio object so that the first audio information contained in the atleast one video object and the second audio information contained in theat least one audio object are reproduced in an audio-orientedreproduction mode.
 2. An optical disk according to claim 1, wherein thesecond reproduction path information includes offset information fordesignating a range to be reproduced of the first audio informationcontained in the at least one video object.
 3. A reproduction apparatusfor reproducing information stored in an optical disk according to claim1, the reproduction apparatus comprising: a reproduction modedetermination section for determining whether a reproduction mode is thevideo-oriented reproduction mode or the audio-oriented reproductionmode; a reproduction section for reproducing the video information andthe first audio information contained in the at least one video objectbased on the first reproduction path information in the case where thereproduction mode is the video-oriented reproduction mode, and forreproducing the first audio information contained in the at least onevideo object and the second audio information contained in the at leastone audio object based on the second reproduction path information inthe case where the reproduction mode is the audio-oriented reproductionmode.
 4. A reproduction apparatus according to claim 3, wherein thesecond reproduction path information includes offset information fordesignating a range to be reproduced of the first audio informationcontained in the at least one video object, the reproducing apparatusreproduces a portion of the first audio information contained in the atleast one video object in accordance with the offset information.
 5. Areproduction apparatus according to claim 3, wherein the reproductionmode can be switched in accordance with an input by a user.
 6. Areproduction apparatus according to claim 3, wherein the reproductionapparatus further comprises a video output terminal for outputting thevideo information, the reproduction mode being switched in accordancewith a state of connection of the video output terminal.
 7. Areproduction apparatus according to claim 3, wherein the reproductionapparatus is a reproduction apparatus to be mounted in an automobile,the reproduction mode being switched in accordance with a state ofmotion of the automobile.
 8. A reproduction method for reproducinginformation stored in an optical disk according to claim 1, thereproduction method comprising the steps of: determining whether areproduction mode is the video-oriented reproduction mode or theaudio-oriented reproduction mode; reproducing the video information andthe first audio information contained in the at least one video objectbased on the first reproduction path information in the case where thereproduction mode is the video-oriented reproduction mode; andreproducing the first audio information contained in the at least onevideo object and the second audio information contained in the at leastone audio object based on the second reproduction path information inthe case where the reproduction mode is the audio-oriented reproductionmode.